Low-latency multi-speaker speech recognition

ABSTRACT

Systems and processes for operating an intelligent automated assistant are provided. In one example, a method includes receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources. The method further includes obtaining a target speaker representation, which represents speech characteristics of the target speaker; and determining, using a learning network, probability distributions of phonetic elements directly from the mixed speech data. The inputs of the learning network include the mixed speech data and the target speaker representation. An output of the learning network includes the probability distributions of phonetic elements. The method further includes generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response to the target speaker based on the text corresponding to the utterances of the target speaker.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. provisional patent application No. 62/826,862, entitled “LOW-LATENCY MULTI-SPEAKER SPEECH RECOGNITION,” filed on Mar. 29, 2019, and claims priority to U.S. provisional patent application No. 62/751,341, entitled “LEVERAGING ON SIRI SPEAKER PROFILE AND ATTENTION FOR LOW-LATENCY MULTI-TALKER SPEECH RECOGNITION,” filed on Oct. 26, 2018. The contents of which are incorporated by reference in their entirety for all purposes.

FIELD

This relates generally to intelligent automated assistants and, more specifically, to performing speech recognition in a multi-speaker environment.

BACKGROUND

Intelligent automated assistants (or virtual assistants) can provide a beneficial interface between human users and electronic devices. Such assistants can allow users to interact with devices or systems using natural language in spoken and/or text forms. For example, a user can provide a speech input including a user request to a virtual assistant operating on an electronic device. The virtual assistant can interpret the user's intent from the speech input and operationalize the user's intent into tasks. The tasks can then be performed by executing one or more services of the electronic device, and a relevant output responsive to the user request can be returned to the user.

Often times, a virtual assistant may receive speech inputs from mixed audio sources in a multi-speaker environment. For example, the speech inputs may include utterances from a target speaker and utterances from one or more interfering audio sources (e.g., people chatting in the background, utterances from TV, etc.). The utterances may overlap because multiple speakers are speaking simultaneously. Accurately recognizing the speech input from the target speaker is often challenging due to the interferences. Sometimes, the virtual assistant may not even identify which speaker is the target speaker. As a result, the virtual assistant may not be able to perform speech recognition correctly and/or provide an appropriate response. Accordingly, there is a need to efficiently and accurately perform speech recognition of speech inputs from the target speaker in a multi-speaker environment.

SUMMARY

Systems and processes for performing speech recognition in a multi-speaker environment by a virtual assistant are provided. In one embodiment, a method for performing speech-to-text conversion in a multi-speaker environment by a virtual assistant is provided. The method is performed at an electronic device with one or more processors and memory. The method includes receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The method further includes obtaining a target speaker representation, which represents speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The method further includes determining, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data. The inputs of the second learning network include the mixed speech data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements. The first learning network and the second learning network are different learning networks. The method further includes generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response to the target speaker based on the text corresponding to the utterances of the target speaker.

Example non-transitory computer-readable media are disclosed herein. An example non-transitory computer-readable storage medium stores one or more programs. The one or more programs comprise instructions which, when executed by one or more processors of an electronic device, cause the electronic device to receive mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The one or more programs include further instructions that cause the electronic device to obtain a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The one or more programs further include instructions that cause the electronic device to determine, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data. Inputs of the second learning network include the mixed speech data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements. The first learning network and the second learning network are different learning networks. The one or more programs include further instructions that cause the electronic device to generate text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and provide a response to the target speaker based on the text corresponding to the utterances of the target speaker.

Example electronic devices are disclosed herein. An example electronic device comprises one or more processors; a memory; and one or more programs, where the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The one or more programs include further instructions for obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The one or more programs include further instructions for determining, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data. The inputs of the second learning network include the mixed speech data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements. The one or more programs include further instructions for generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response to the target speaker based on the text corresponding to the utterances of the target speaker.

Example methods are disclosed herein. An example method includes, at one or more electronic devices having one or more processors and memory, receiving a first set of training data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The method further includes receiving a second set of training data representing only the utterances of the target speaker; and obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The method further includes training the speaker-aware acoustic model for speech recognition based on the first set of training data and the second set of training data. Each iteration of the training includes determining, using a second learning network, probability distributions of phonetic elements directly from the first set of training data. Inputs of the second learning network include a portion of the first set of training data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements corresponding to the portion of the first set of training data. The first learning network and the second learning network are different learning networks. Each iteration of the training further includes generating text corresponding to the utterances of the target speaker in the portion of the first set of training data based on the probability distributions of the phonetic elements corresponding to the portion of the first set of training data; and adjusting one or more parameters of the second learning network based on the text corresponding to the utterances of the target speaker in the portion of the first set of training data and based on corresponding portion of the second set of training data.

Example non-transitory computer-readable media are disclosed herein. An example non-transitory computer-readable storage medium stores one or more programs. The one or more programs comprise instructions which, when executed by one or more processors of an electronic device, cause the electronic device to receive a first set of training data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The one or more programs include further instructions that cause the electronic device to receive a second set of training data representing only the utterances of the target speaker; and obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The one or more programs include further instructions that cause the electronic device to train the speaker-aware acoustic model for speech recognition based on the first set of training data and the second set of training data. Each iteration of the training includes determining, using a second learning network, probability distributions of phonetic elements directly from the first set of training data. Inputs of the second learning network include a portion of the first set of training data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements corresponding to the portion of the first set of training data. The first learning network and the second learning network are different learning networks. Each iteration of the training further includes generating text corresponding to the utterances of the target speaker in the portion of the first set of training data based on the probability distributions of the phonetic elements corresponding to the portion of the first set of training data; and adjusting one or more parameters of the second learning network based on the text corresponding to the utterances of the target speaker in the portion of the first set of training data and based on corresponding portion of the second set of training data.

An example electronic device comprises one or more processors; a memory; and one or more programs, where the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for receiving a first set of training data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The one or more programs include further instructions for receiving a second set of training data representing only the utterances of the target speaker; and obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The one or more programs include further instructions for training the speaker-aware acoustic model for speech recognition based on the first set of training data and the second set of training data. Each iteration of the training includes determining, using a second learning network, probability distributions of phonetic elements directly from the first set of training data. Inputs of the second learning network include a portion of the first set of training data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements corresponding to the portion of the first set of training data. The first learning network and the second learning network are different learning networks. Each iteration of the training further includes generating text corresponding to the utterances of the target speaker in the portion of the first set of training data based on the probability distributions of the phonetic elements corresponding to the portion of the first set of training data; and adjusting one or more parameters of the second learning network based on the text corresponding to the utterances of the target speaker in the portion of the first set of training data and based on corresponding portion of the second set of training data.

An example electronic device comprises means for receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The electronic device further includes means for obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The electronic device further includes means for determining, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data. The inputs of the second learning network include the mixed speech data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements. The first learning network and the second learning network are different learning networks. The electronic device further includes means for generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response to the target speaker based on the text corresponding to the utterances of the target speaker.

An example electronic device comprises means for receiving a first set of training data representing utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. The electronic device includes further means for receiving a second set of training data representing only the utterances of the target speaker; and obtaining a target speaker representation representing speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification. The electronic device includes further means for training the speaker-aware acoustic model for speech recognition based on the first set of training data and the second set of training data. Each iteration of the training includes determining, using a second learning network, probability distributions of phonetic elements directly from the first set of training data. Inputs of the second learning network include a portion of the first set of training data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements corresponding to the portion of the first set of training data. The first learning network and the second learning network are different learning networks. Each iteration of the training further includes generating text corresponding to the utterances of the target speaker in the portion of the first set of training data based on the probability distributions of the phonetic elements corresponding to the portion of the first set of training data; and adjusting one or more parameters of the learning network based on the text corresponding to the utterances of the target speaker in the portion of the first set of training data and based on corresponding portion of the second set of training data.

Techniques for performing speech recognition in a multi-speaker environment are desirable. In particular, it is desirable to detect speech inputs from a target speaker in the presence of one or more interfering audio sources (e.g., people chatting in background, utterances from a TV, etc.). In a multi-speaker environment, a virtual assistant may not provide a proper response to the target speaker if it processes all received speech inputs as if they were from the target speaker. Thus, properly identifying the speech inputs of the target speaker from speech inputs of the interfering sources can reduce the rate of erroneous speech recognition and improve the efficiencies of the virtual assistant (e.g., the target speaker does not need to speak to the virtual assistant in a quiet environment). This in turn provides a more efficient and friendly user interface, thereby enhancing the user experience when interacting with the virtual assistant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a system and environment for implementing a digital assistant, according to various examples.

FIG. 2A is a block diagram illustrating a portable multifunction device implementing the client-side portion of a digital assistant, according to various examples.

FIG. 2B is a block diagram illustrating exemplary components for event handling, according to various examples.

FIG. 3 illustrates a portable multifunction device implementing the client-side portion of a digital assistant, according to various examples.

FIG. 4 is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface, according to various examples.

FIG. 5A illustrates an exemplary user interface for a menu of applications on a portable multifunction device, according to various examples.

FIG. 5B illustrates an exemplary user interface for a multifunction device with a touch-sensitive surface that is separate from the display, according to various examples.

FIG. 6A illustrates a personal electronic device, according to various examples.

FIG. 6B is a block diagram illustrating a personal electronic device, according to various examples.

FIG. 7A is a block diagram illustrating a digital assistant system or a server portion thereof, according to various examples.

FIG. 7B illustrates the functions of the digital assistant shown in FIG. 7A, according to various examples.

FIG. 7C illustrates a portion of an ontology, according to various examples.

FIG. 8 illustrates a block diagram of a speech-to-text (STT) processing module for performing speech-to-text conversion in a multi-speaker environment using a single learning network, according to various examples.

FIG. 9A illustrates a block diagram of a first embodiment of a learning network for generating senone posterior probability distributions.

FIG. 9B illustrates a block diagram of a second embodiment of a learning network for generating senone posterior probability distributions.

FIG. 9C illustrates a block diagram of a hidden layer used in the second embodiment of a learning network for generating senone posterior probability distributions.

FIG. 10 illustrates a block diagram of training a single learning network for generating senone posterior probability distributions, according to various examples.

FIGS. 11A-11C illustrate an exemplary process for performing speech-to-text conversion in a multi-speaker environment by a virtual assistant, according to various examples.

FIGS. 12A-12D illustrate an exemplary process for training a speaker-aware acoustic model for speech recognition in a multi-speaker environment, according to various examples.

DETAILED DESCRIPTION

In the following description of examples, reference is made to the accompanying drawings in which are shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the various examples.

As described above, it is often desirable to detect speech inputs from a target speaker in the presence of one or more interfering audio sources (e.g., people chatting in background, utterances from a TV, etc.). Existing techniques for performing speech-to-text conversion in a multi-speaker environment often require two separate machine learning networks. That is, one neural network is required for separating the speech inputs of the target speaker from the speech inputs of interfering audio sources, and generating intermediate speech data that represent only the speech inputs of the target speaker. Further, another separate neural network is required for converting the speech data that represent only the speech inputs of the target speaker to text. The requirement of two separate neural network can lead to inefficiency and low accuracy in performing the speech-to-text conversion.

Speaker-aware acoustic models for efficiently performing speech-to-text conversion are described in this application. Using the speaker-aware acoustic models, the techniques described in this application do not require the generation of speech data that represent only the speech inputs of the target speaker. Therefore, a single machine learning network (e.g., a recurrent neural network) can be used to enable a direct conversion of mixed speech data to texts that correspond to the speech inputs of the target speaker. A single learning network can have an input layer, a plurality of hidden layers, and an output layer. In some embodiments, a first hidden layer includes a convolutional layer. The single learning network can further include one or more optional pooling layers disposed between the convolution layer and subsequent hidden layers. In some embodiments, the convolutional layer and the pooling layers are optional. The speaker-aware acoustic models obtain a target speaker representation that uniquely identifies the target speaker. The target speaker representation is used in the speaker-aware acoustic models to improve the accuracy of speech-to-text conversion in a multi-speaker environment, e.g., by conditioning the senone probability distributions to the target speaker representation.

Moreover, the traditional techniques of speaker identification/recognition in a multi-speaker environment are inefficient and error prone. For example, because the traditional techniques use two separate neural networks for performing speech separation and speech recognition, two separate trainings of the networks are thus required with two separate sets of training data. This is often cumbersome and inefficient. For instance, separated clean speech data from multiple audio sources may not be readily available for the purpose of training the neural network for speech separation. Also, interfering audio sources may often vary and thus one set of training data may not be sufficient. The techniques described in this application eliminates the requirement for separating the speeches, and combines the traditional speech separation and the speech recognition steps into one step by using one improved speaker-aware acoustic model. As described in more detail below, the techniques described in this application greatly improve the efficiency in training the model by eliminating the need for an intermediate training target for training the speech separation network and by eliminating the compatibility issues of training two different learning networks (one for speech separation and one for speech recognition). The training can thus be better performed to obtain an improved trained model. In turn, the improved trained model enhances the accuracy and efficiency of speech recognition compared to traditional techniques because the trained model can more accurately recognize the speech inputs from the target speaker in the presence of interfering sources.

Some recently-developed techniques attempt to use a single machine learning network to detect speech inputs in a multi-speaker environment. These techniques do not have a dedicated speaker verification system to extract a speaker vector using a separate acoustic model or machine learning network. Instead, the extraction of the speaker vector is performed during the training of the same acoustic model for speech recognition in a multi-speaker environment. This may result in degraded performance for recognizing target speaker speeches. Further, some of the recently-developed techniques may use attention mechanisms in an attempt to improve the performance. The attention mechanisms used in these techniques often attend to feature vectors extracted from different input audio frames. As a result, the performance of these existing techniques may be degraded because these techniques implicitly assume that each audio frame is dominated by one speaker. But in a multi-speaker environment, it is likely that some audio frames may contain overlapping speech inputs from multiple speakers.

As described in more detail below, techniques described in this application use a dedicated speaker verification system to extract a target speaker vector based on a separate acoustic model or machine learning network. As a result, the target speaker vector so extracted can more adequately and cleanly represent the target speaker's speech characteristics. In turn, the performance of the speaker-aware acoustic model can be improved using a target speaker vector extracted in such a manner. Further, some embodiments described in this application use an improved attention mechanism that can attend to speech inputs from different speakers extracted from a same audio frame. As a result, such embodiments do not assume that each audio frame is dominated by one speaker. Rather, using the attention mechanism described in this application, the performance of speech recognition in a multi-speaker environment do not degrade, and may improve, even if there are overlapping speech inputs from multiple speakers in some audio frames.

Although the following description uses terms “first,” “second,” etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, a first portion of a learning network could be termed a second portion, and, similarly, a second portion could be termed a first portion, without departing from the scope of the various described examples. The first portion and the second portion are both portions of a learning network and, in some cases, are separate and different portions.

The terminology used in the description of the various described examples herein is for the purpose of describing particular examples only and is not intended to be limiting. As used in the description of the various described examples and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” may be construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context.

1. System and Environment

FIG. 1 illustrates a block diagram of system 100 according to various examples. In some examples, system 100 implements a digital assistant. The terms “digital assistant,” “virtual assistant,” “intelligent automated assistant,” or “automatic digital assistant” refer to any information processing system that interprets natural language input in spoken and/or textual form to infer user intent, and performs actions based on the inferred user intent. For example, to act on an inferred user intent, the system performs one or more of the following: identifying a task flow with steps and parameters designed to accomplish the inferred user intent, inputting specific requirements from the inferred user intent into the task flow; executing the task flow by invoking programs, methods, services, APIs, or the like; and generating output responses to the user in an audible (e.g., speech) and/or visual form.

Specifically, a digital assistant is capable of accepting a user request at least partially in the form of a natural language command, request, statement, narrative, and/or inquiry. Typically, the user request seeks either an informational answer or performance of a task by the digital assistant. A satisfactory response to the user request includes a provision of the requested informational answer, a performance of the requested task, or a combination of the two. For example, a user asks the digital assistant a question, such as “Where am I right now?” Based on the user's current location, the digital assistant answers, “You are in Central Park near the west gate.” The user also requests the performance of a task, for example, “Please invite my friends to my girlfriend's birthday party next week.” In response, the digital assistant can acknowledge the request by saying “Yes, right away,” and then send a suitable calendar invite on behalf of the user to each of the user's friends listed in the user's electronic address book. During performance of a requested task, the digital assistant sometimes interacts with the user in a continuous dialogue involving multiple exchanges of information over an extended period of time. There are numerous other ways of interacting with a digital assistant to request information or performance of various tasks. In addition to providing verbal responses and taking programmed actions, the digital assistant also provides responses in other visual or audio forms, e.g., as text, alerts, music, videos, animations, etc.

As shown in FIG. 1, in some examples, a digital assistant is implemented according to a client-server model. The digital assistant includes client-side portion 102 (hereafter “DA client 102”) executed on user device 104 and server-side portion 106 (hereafter “DA server 106”) executed on server system 108. DA client 102 communicates with DA server 106 through one or more networks 110. DA client 102 provides client-side functionalities such as user-facing input and output processing and communication with DA server 106. DA server 106 provides server-side functionalities for any number of DA clients 102 each residing on a respective user device 104.

In some examples, DA server 106 includes client-facing I/O interface 112, one or more processing modules 114, data and models 116, and I/O interface to external services 118. The client-facing I/O interface 112 facilitates the client-facing input and output processing for DA server 106. One or more processing modules 114 utilize data and models 116 to process speech input and determine the user's intent based on natural language input. Further, one or more processing modules 114 perform task execution based on inferred user intent. In some examples, DA server 106 communicates with external services 120 through network(s) 110 for task completion or information acquisition. I/O interface to external services 118 facilitates such communications.

User device 104 can be any suitable electronic device. In some examples, user device 104 is a portable multifunctional device (e.g., device 200, described below with reference to FIG. 2A), a multifunctional device (e.g., device 400, described below with reference to FIG. 4), or a personal electronic device (e.g., device 600, described below with reference to FIG. 6A-6B.) A portable multifunctional device is, for example, a mobile telephone that also includes other functions, such as PDA and/or music player functions. Specific examples of portable multifunction devices include the Apple Watch®, iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other examples of portable multifunction devices include, without limitation, earphones/headphones, speakers, and laptop or tablet computers. Further, in some examples, user device 104 is a non-portable multifunctional device. In particular, user device 104 is a desktop computer, a game console, a speaker, a television, or a television set-top box. In some examples, user device 104 includes a touch-sensitive surface (e.g., touch screen displays and/or touchpads). Further, user device 104 optionally includes one or more other physical user-interface devices, such as a physical keyboard, a mouse, and/or a joystick. Various examples of electronic devices, such as multifunctional devices, are described below in greater detail.

Examples of communication network(s) 110 include local area networks (LAN) and wide area networks (WAN), e.g., the Internet. Communication network(s) 110 is implemented using any known network protocol, including various wired or wireless protocols, such as, for example, Ethernet, Universal Serial Bus (USB), FIREWIRE, Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wi-Fi, voice over Internet Protocol (VoIP), Wi-MAX, or any other suitable communication protocol.

Server system 108 is implemented on one or more standalone data processing apparatus or a distributed network of computers. In some examples, server system 108 also employs various virtual devices and/or services of third-party service providers (e.g., third-party cloud service providers) to provide the underlying computing resources and/or infrastructure resources of server system 108.

In some examples, user device 104 communicates with DA server 106 via second user device 122. Second user device 122 is similar or identical to user device 104. For example, second user device 122 is similar to devices 200, 400, or 600 described below with reference to FIGS. 2A, 4, and 6A-6B. User device 104 is configured to communicatively couple to second user device 122 via a direct communication connection, such as Bluetooth, NFC, BTLE, or the like, or via a wired or wireless network, such as a local Wi-Fi network. In some examples, second user device 122 is configured to act as a proxy between user device 104 and DA server 106. For example, DA client 102 of user device 104 is configured to transmit information (e.g., a user request received at user device 104) to DA server 106 via second user device 122. DA server 106 processes the information and returns relevant data (e.g., data content responsive to the user request) to user device 104 via second user device 122.

In some examples, user device 104 is configured to communicate abbreviated requests for data to second user device 122 to reduce the amount of information transmitted from user device 104. Second user device 122 is configured to determine supplemental information to add to the abbreviated request to generate a complete request to transmit to DA server 106. This system architecture can advantageously allow user device 104 having limited communication capabilities and/or limited battery power (e.g., a watch or a similar compact electronic device) to access services provided by DA server 106 by using second user device 122, having greater communication capabilities and/or battery power (e.g., a mobile phone, laptop computer, tablet computer, or the like), as a proxy to DA server 106. While only two user devices 104 and 122 are shown in FIG. 1, it should be appreciated that system 100, in some examples, includes any number and type of user devices configured in this proxy configuration to communicate with DA server system 106.

Although the digital assistant shown in FIG. 1 includes both a client-side portion (e.g., DA client 102) and a server-side portion (e.g., DA server 106), in some examples, the functions of a digital assistant are implemented as a standalone application installed on a user device. In addition, the divisions of functionalities between the client and server portions of the digital assistant can vary in different implementations. For instance, in some examples, the DA client is a thin-client that provides only user-facing input and output processing functions, and delegates all other functionalities of the digital assistant to a backend server.

2. Electronic Devices

Attention is now directed toward embodiments of electronic devices for implementing the client-side portion of a digital assistant. FIG. 2A is a block diagram illustrating portable multifunction device 200 with touch-sensitive display system 212 in accordance with some embodiments. Touch-sensitive display 212 is sometimes called a “touch screen” for convenience and is sometimes known as or called a “touch-sensitive display system.” Device 200 includes memory 202 (which optionally includes one or more computer-readable storage mediums), memory controller 222, one or more processing units (CPUs) 220, peripherals interface 218, RF circuitry 208, audio circuitry 210, speaker 211, microphone 213, input/output (I/O) subsystem 206, other input control devices 216, and external port 224. Device 200 optionally includes one or more optical sensors 264. Device 200 optionally includes one or more contact intensity sensors 265 for detecting intensity of contacts on device 200 (e.g., a touch-sensitive surface such as touch-sensitive display system 212 of device 200). Device 200 optionally includes one or more tactile output generators 267 for generating tactile outputs on device 200 (e.g., generating tactile outputs on a touch-sensitive surface such as touch-sensitive display system 212 of device 200 or touchpad 455 of device 400). These components optionally communicate over one or more communication buses or signal lines 203.

As used in the specification and claims, the term “intensity” of a contact on a touch-sensitive surface refers to the force or pressure (force per unit area) of a contact (e.g., a finger contact) on the touch-sensitive surface, or to a substitute (proxy) for the force or pressure of a contact on the touch-sensitive surface. The intensity of a contact has a range of values that includes at least four distinct values and more typically includes hundreds of distinct values (e.g., at least 256). Intensity of a contact is, optionally, determined (or measured) using various approaches and various sensors or combinations of sensors. For example, one or more force sensors underneath or adjacent to the touch-sensitive surface are, optionally, used to measure force at various points on the touch-sensitive surface. In some implementations, force measurements from multiple force sensors are combined (e.g., a weighted average) to determine an estimated force of a contact. Similarly, a pressure-sensitive tip of a stylus is, optionally, used to determine a pressure of the stylus on the touch-sensitive surface. Alternatively, the size of the contact area detected on the touch-sensitive surface and/or changes thereto, the capacitance of the touch-sensitive surface proximate to the contact and/or changes thereto, and/or the resistance of the touch-sensitive surface proximate to the contact and/or changes thereto are, optionally, used as a substitute for the force or pressure of the contact on the touch-sensitive surface. In some implementations, the substitute measurements for contact force or pressure are used directly to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is described in units corresponding to the substitute measurements). In some implementations, the substitute measurements for contact force or pressure are converted to an estimated force or pressure, and the estimated force or pressure is used to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is a pressure threshold measured in units of pressure). Using the intensity of a contact as an attribute of a user input allows for user access to additional device functionality that may otherwise not be accessible by the user on a reduced-size device with limited real estate for displaying affordances (e.g., on a touch-sensitive display) and/or receiving user input (e.g., via a touch-sensitive display, a touch-sensitive surface, or a physical/mechanical control such as a knob or a button).

As used in the specification and claims, the term “tactile output” refers to physical displacement of a device relative to a previous position of the device, physical displacement of a component (e.g., a touch-sensitive surface) of a device relative to another component (e.g., housing) of the device, or displacement of the component relative to a center of mass of the device that will be detected by a user with the user's sense of touch. For example, in situations where the device or the component of the device is in contact with a surface of a user that is sensitive to touch (e.g., a finger, palm, or other part of a user's hand), the tactile output generated by the physical displacement will be interpreted by the user as a tactile sensation corresponding to a perceived change in physical characteristics of the device or the component of the device. For example, movement of a touch-sensitive surface (e.g., a touch-sensitive display or trackpad) is, optionally, interpreted by the user as a “down click” or “up click” of a physical actuator button. In some cases, a user will feel a tactile sensation such as an “down click” or “up click” even when there is no movement of a physical actuator button associated with the touch-sensitive surface that is physically pressed (e.g., displaced) by the user's movements. As another example, movement of the touch-sensitive surface is, optionally, interpreted or sensed by the user as “roughness” of the touch-sensitive surface, even when there is no change in smoothness of the touch-sensitive surface. While such interpretations of touch by a user will be subject to the individualized sensory perceptions of the user, there are many sensory perceptions of touch that are common to a large majority of users. Thus, when a tactile output is described as corresponding to a particular sensory perception of a user (e.g., an “up click,” a “down click,” “roughness”), unless otherwise stated, the generated tactile output corresponds to physical displacement of the device or a component thereof that will generate the described sensory perception for a typical (or average) user.

It should be appreciated that device 200 is only one example of a portable multifunction device, and that device 200 optionally has more or fewer components than shown, optionally combines two or more components, or optionally has a different configuration or arrangement of the components. The various components shown in FIG. 2A are implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and/or application-specific integrated circuits.

Memory 202 includes one or more computer-readable storage mediums. The computer-readable storage mediums are, for example, tangible and non-transitory. Memory 202 includes high-speed random access memory and also includes non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Memory controller 222 controls access to memory 202 by other components of device 200.

In some examples, a non-transitory computer-readable storage medium of memory 202 is used to store instructions (e.g., for performing aspects of processes described below) for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In other examples, the instructions (e.g., for performing aspects of the processes described below) are stored on a non-transitory computer-readable storage medium (not shown) of the server system 108 or are divided between the non-transitory computer-readable storage medium of memory 202 and the non-transitory computer-readable storage medium of server system 108.

Peripherals interface 218 is used to couple input and output peripherals of the device to CPU 220 and memory 202. The one or more processors 220 run or execute various software programs and/or sets of instructions stored in memory 202 to perform various functions for device 200 and to process data. In some embodiments, peripherals interface 218, CPU 220, and memory controller 222 are implemented on a single chip, such as chip 204. In some other embodiments, they are implemented on separate chips.

RF (radio frequency) circuitry 208 receives and sends RF signals, also called electromagnetic signals. RF circuitry 208 converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry 208 optionally includes well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry 208 optionally communicates with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The RF circuitry 208 optionally includes well-known circuitry for detecting near field communication (NFC) fields, such as by a short-range communication radio. The wireless communication optionally uses any of a plurality of communications standards, protocols, and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Bluetooth Low Energy (BTLE), Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and/or IEEE 802.11ac), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document.

Audio circuitry 210, speaker 211, and microphone 213 provide an audio interface between a user and device 200. Audio circuitry 210 receives audio data from peripherals interface 218, converts the audio data to an electrical signal, and transmits the electrical signal to speaker 211. Speaker 211 converts the electrical signal to human-audible sound waves. Audio circuitry 210 also receives electrical signals converted by microphone 213 from sound waves. Audio circuitry 210 converts the electrical signal to audio data and transmits the audio data to peripherals interface 218 for processing. Audio data are retrieved from and/or transmitted to memory 202 and/or RF circuitry 208 by peripherals interface 218. In some embodiments, audio circuitry 210 also includes a headset jack (e.g., 312, FIG. 3). The headset jack provides an interface between audio circuitry 210 and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone).

I/O subsystem 206 couples input/output peripherals on device 200, such as touch screen 212 and other input control devices 216, to peripherals interface 218. I/O subsystem 206 optionally includes display controller 256, optical sensor controller 258, intensity sensor controller 259, haptic feedback controller 261, and one or more input controllers 260 for other input or control devices. The one or more input controllers 260 receive/send electrical signals from/to other input control devices 216. The other input control devices 216 optionally include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s) 260 are, optionally, coupled to any (or none) of the following: a keyboard, an infrared port, a USB port, and a pointer device such as a mouse. The one or more buttons (e.g., 308, FIG. 3) optionally include an up/down button for volume control of speaker 211 and/or microphone 213. The one or more buttons optionally include a push button (e.g., 306, FIG. 3).

A quick press of the push button disengages a lock of touch screen 212 or begin a process that uses gestures on the touch screen to unlock the device, as described in U.S. patent application Ser. No. 11/322,549, “Unlocking a Device by Performing Gestures on an Unlock Image,” filed Dec. 23, 2005, U.S. Pat. No. 7,657,849, which is hereby incorporated by reference in its entirety. A longer press of the push button (e.g., 306) turns power to device 200 on or off. The user is able to customize a functionality of one or more of the buttons. Touch screen 212 is used to implement virtual or soft buttons and one or more soft keyboards.

Touch-sensitive display 212 provides an input interface and an output interface between the device and a user. Display controller 256 receives and/or sends electrical signals from/to touch screen 212. Touch screen 212 displays visual output to the user. The visual output includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output correspond to user-interface objects.

Touch screen 212 has a touch-sensitive surface, sensor, or set of sensors that accepts input from the user based on haptic and/or tactile contact. Touch screen 212 and display controller 256 (along with any associated modules and/or sets of instructions in memory 202) detect contact (and any movement or breaking of the contact) on touch screen 212 and convert the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages, or images) that are displayed on touch screen 212. In an exemplary embodiment, a point of contact between touch screen 212 and the user corresponds to a finger of the user.

Touch screen 212 uses LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies may be used in other embodiments. Touch screen 212 and display controller 256 detect contact and any movement or breaking thereof using any of a plurality of touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch screen 212. In an exemplary embodiment, projected mutual capacitance sensing technology is used, such as that found in the iPhone® and iPod Touch® from Apple Inc. of Cupertino, Calif.

A touch-sensitive display in some embodiments of touch screen 212 is analogous to the multi-touch sensitive touchpads described in the following U.S. Pat. No. 6,323,846 (Westerman et al.), U.S. Pat. No. 6,570,557 (Westerman et al.), and/or U.S. Pat. No. 6,677,932 (Westerman), and/or U.S. Patent Publication 2002/0015024A1, each of which is hereby incorporated by reference in its entirety. However, touch screen 212 displays visual output from device 200, whereas touch-sensitive touchpads do not provide visual output.

A touch-sensitive display in some embodiments of touch screen 212 is as described in the following applications: (1) U.S. patent application Ser. No. 11/381,313, “Multipoint Touch Surface Controller,” filed May 2, 2006; (2) U.S. patent application Ser. No. 10/840,862, “Multipoint Touchscreen,” filed May 6, 2004; (3) U.S. patent application Ser. No. 10/903,964, “Gestures For Touch Sensitive Input Devices,” filed Jul. 30, 2004; (4) U.S. patent application Ser. No. 11/048,264, “Gestures For Touch Sensitive Input Devices,” filed Jan. 31, 2005; (5) U.S. patent application Ser. No. 11/038,590, “Mode-Based Graphical User Interfaces For Touch Sensitive Input Devices,” filed Jan. 18, 2005; (6) U.S. patent application Ser. No. 11/228,758, “Virtual Input Device Placement On A Touch Screen User Interface,” filed Sep. 16, 2005; (7) U.S. patent application Ser. No. 11/228,700, “Operation Of A Computer With A Touch Screen Interface,” filed Sep. 16, 2005; (8) U.S. patent application Ser. No. 11/228,737, “Activating Virtual Keys Of A Touch-Screen Virtual Keyboard,” filed Sep. 16, 2005; and (9) U.S. patent application Ser. No. 11/367,749, “Multi-Functional Hand-Held Device,” filed Mar. 3, 2006. All of these applications are incorporated by reference herein in their entirety.

Touch screen 212 has, for example, a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 160 dpi. The user makes contact with touch screen 212 using any suitable object or appendage, such as a stylus, a finger, and so forth. In some embodiments, the user interface is designed to work primarily with finger-based contacts and gestures, which can be less precise than stylus-based input due to the larger area of contact of a finger on the touch screen. In some embodiments, the device translates the rough finger-based input into a precise pointer/cursor position or command for performing the actions desired by the user.

In some embodiments, in addition to the touch screen, device 200 includes a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad is a touch-sensitive surface that is separate from touch screen 212 or an extension of the touch-sensitive surface formed by the touch screen.

Device 200 also includes power system 262 for powering the various components. Power system 262 includes a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices.

Device 200 also includes one or more optical sensors 264. FIG. 2A shows an optical sensor coupled to optical sensor controller 258 in I/O subsystem 206. Optical sensor 264 includes charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor 264 receives light from the environment, projected through one or more lenses, and converts the light to data representing an image. In conjunction with imaging module 243 (also called a camera module), optical sensor 264 captures still images or video. In some embodiments, an optical sensor is located on the back of device 200, opposite touch screen display 212 on the front of the device so that the touch screen display is used as a viewfinder for still and/or video image acquisition. In some embodiments, an optical sensor is located on the front of the device so that the user's image is obtained for video conferencing while the user views the other video conference participants on the touch screen display. In some embodiments, the position of optical sensor 264 can be changed by the user (e.g., by rotating the lens and the sensor in the device housing) so that a single optical sensor 264 is used along with the touch screen display for both video conferencing and still and/or video image acquisition.

Device 200 optionally also includes one or more contact intensity sensors 265. FIG. 2A shows a contact intensity sensor coupled to intensity sensor controller 259 in I/O subsystem 206. Contact intensity sensor 265 optionally includes one or more piezoresistive strain gauges, capacitive force sensors, electric force sensors, piezoelectric force sensors, optical force sensors, capacitive touch-sensitive surfaces, or other intensity sensors (e.g., sensors used to measure the force (or pressure) of a contact on a touch-sensitive surface). Contact intensity sensor 265 receives contact intensity information (e.g., pressure information or a proxy for pressure information) from the environment. In some embodiments, at least one contact intensity sensor is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system 212). In some embodiments, at least one contact intensity sensor is located on the back of device 200, opposite touch screen display 212, which is located on the front of device 200.

Device 200 also includes one or more proximity sensors 266. FIG. 2A shows proximity sensor 266 coupled to peripherals interface 218. Alternately, proximity sensor 266 is coupled to input controller 260 in I/O subsystem 206. Proximity sensor 266 is performed as described in U.S. patent application Ser. No. 11/241,839, “Proximity Detector In Handheld Device”; Ser. No. 11/240,788, “Proximity Detector In Handheld Device”; Ser. No. 11/620,702, “Using Ambient Light Sensor To Augment Proximity Sensor Output”; Ser. No. 11/586,862, “Automated Response To And Sensing Of User Activity In Portable Devices”; and Ser. No. 11/638,251, “Methods And Systems For Automatic Configuration Of Peripherals,” which are hereby incorporated by reference in their entirety. In some embodiments, the proximity sensor turns off and disables touch screen 212 when the multifunction device is placed near the user's ear (e.g., when the user is making a phone call).

Device 200 optionally also includes one or more tactile output generators 267. FIG. 2A shows a tactile output generator coupled to haptic feedback controller 261 in I/O subsystem 206. Tactile output generator 267 optionally includes one or more electroacoustic devices such as speakers or other audio components and/or electromechanical devices that convert energy into linear motion such as a motor, solenoid, electroactive polymer, piezoelectric actuator, electrostatic actuator, or other tactile output generating component (e.g., a component that converts electrical signals into tactile outputs on the device). Contact intensity sensor 265 receives tactile feedback generation instructions from haptic feedback module 233 and generates tactile outputs on device 200 that are capable of being sensed by a user of device 200. In some embodiments, at least one tactile output generator is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system 212) and, optionally, generates a tactile output by moving the touch-sensitive surface vertically (e.g., in/out of a surface of device 200) or laterally (e.g., back and forth in the same plane as a surface of device 200). In some embodiments, at least one tactile output generator sensor is located on the back of device 200, opposite touch screen display 212, which is located on the front of device 200.

Device 200 also includes one or more accelerometers 268. FIG. 2A shows accelerometer 268 coupled to peripherals interface 218. Alternately, accelerometer 268 is coupled to an input controller 260 in I/O subsystem 206. Accelerometer 268 performs, for example, as described in U.S. Patent Publication No. 20050190059, “Acceleration-based Theft Detection System for Portable Electronic Devices,” and U.S. Patent Publication No. 20060017692, “Methods And Apparatuses For Operating A Portable Device Based On An Accelerometer,” both of which are incorporated by reference herein in their entirety. In some embodiments, information is displayed on the touch screen display in a portrait view or a landscape view based on an analysis of data received from the one or more accelerometers. Device 200 optionally includes, in addition to accelerometer(s) 268, a magnetometer (not shown) and a GPS (or GLONASS or other global navigation system) receiver (not shown) for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device 200.

In some embodiments, the software components stored in memory 202 include operating system 226, communication module (or set of instructions) 228, contact/motion module (or set of instructions) 230, graphics module (or set of instructions) 232, text input module (or set of instructions) 234, Global Positioning System (GPS) module (or set of instructions) 235, Digital Assistant Client Module 229, and applications (or sets of instructions) 236. Further, memory 202 stores data and models, such as user data and models 231. Furthermore, in some embodiments, memory 202 (FIG. 2A) or 470 (FIG. 4) stores device/global internal state 257, as shown in FIGS. 2A and 4. Device/global internal state 257 includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch screen display 212; sensor state, including information obtained from the device's various sensors and input control devices 216; and location information concerning the device's location and/or attitude.

Operating system 226 (e.g., Darwin, RTXC, LINUX, UNIX, OS X, iOS, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components.

Communication module 228 facilitates communication with other devices over one or more external ports 224 and also includes various software components for handling data received by RF circuitry 208 and/or external port 224. External port 224 (e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.). In some embodiments, the external port is a multi-pin (e.g., 30-pin) connector that is the same as, or similar to and/or compatible with, the 30-pin connector used on iPod® (trademark of Apple Inc.) devices.

Contact/motion module 230 optionally detects contact with touch screen 212 (in conjunction with display controller 256) and other touch-sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module 230 includes various software components for performing various operations related to detection of contact, such as determining if contact has occurred (e.g., detecting a finger-down event), determining an intensity of the contact (e.g., the force or pressure of the contact or a substitute for the force or pressure of the contact), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module 230 receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, optionally includes determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations are, optionally, applied to single contacts (e.g., one finger contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module 230 and display controller 256 detect contact on a touchpad.

In some embodiments, contact/motion module 230 uses a set of one or more intensity thresholds to determine whether an operation has been performed by a user (e.g., to determine whether a user has “clicked” on an icon). In some embodiments, at least a subset of the intensity thresholds are determined in accordance with software parameters (e.g., the intensity thresholds are not determined by the activation thresholds of particular physical actuators and can be adjusted without changing the physical hardware of device 200). For example, a mouse “click” threshold of a trackpad or touch screen display can be set to any of a large range of predefined threshold values without changing the trackpad or touch screen display hardware. Additionally, in some implementations, a user of the device is provided with software settings for adjusting one or more of the set of intensity thresholds (e.g., by adjusting individual intensity thresholds and/or by adjusting a plurality of intensity thresholds at once with a system-level click “intensity” parameter).

Contact/motion module 230 optionally detects a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns (e.g., different motions, timings, and/or intensities of detected contacts). Thus, a gesture is, optionally, detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (liftoff) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (liftoff) event.

Graphics module 232 includes various known software components for rendering and displaying graphics on touch screen 212 or other display, including components for changing the visual impact (e.g., brightness, transparency, saturation, contrast, or other visual property) of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including, without limitation, text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations, and the like.

In some embodiments, graphics module 232 stores data representing graphics to be used. Each graphic is, optionally, assigned a corresponding code. Graphics module 232 receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller 256.

Haptic feedback module 233 includes various software components for generating instructions used by tactile output generator(s) 267 to produce tactile outputs at one or more locations on device 200 in response to user interactions with device 200.

Text input module 234, which is, in some examples, a component of graphics module 232, provides soft keyboards for entering text in various applications (e.g., contacts 237, email 240, IM 241, browser 247, and any other application that needs text input).

GPS module 235 determines the location of the device and provides this information for use in various applications (e.g., to telephone 238 for use in location-based dialing; to camera 243 as picture/video metadata; and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets).

Digital assistant client module 229 includes various client-side digital assistant instructions to provide the client-side functionalities of the digital assistant. For example, digital assistant client module 229 is capable of accepting voice input (e.g., speech input), text input, touch input, and/or gestural input through various user interfaces (e.g., microphone 213, accelerometer(s) 268, touch-sensitive display system 212, optical sensor(s) 264, other input control devices 216, etc.) of portable multifunction device 200. Digital assistant client module 229 is also capable of providing output in audio (e.g., speech output), visual, and/or tactile forms through various output interfaces (e.g., speaker 211, touch-sensitive display system 212, tactile output generator(s) 267, etc.) of portable multifunction device 200. For example, output is provided as voice, sound, alerts, text messages, menus, graphics, videos, animations, vibrations, and/or combinations of two or more of the above. During operation, digital assistant client module 229 communicates with DA server 106 using RF circuitry 208.

User data and models 231 include various data associated with the user (e.g., user-specific vocabulary data, user preference data, user-specified name pronunciations, data from the user's electronic address book, to-do lists, shopping lists, etc.) to provide the client-side functionalities of the digital assistant. Further, user data and models 231 include various models (e.g., speech recognition models, statistical language models, natural language processing models, ontology, task flow models, service models, etc.) for processing user input and determining user intent.

In some examples, digital assistant client module 229 utilizes the various sensors, subsystems, and peripheral devices of portable multifunction device 200 to gather additional information from the surrounding environment of the portable multifunction device 200 to establish a context associated with a user, the current user interaction, and/or the current user input. In some examples, digital assistant client module 229 provides the contextual information or a subset thereof with the user input to DA server 106 to help infer the user's intent. In some examples, the digital assistant also uses the contextual information to determine how to prepare and deliver outputs to the user. Contextual information is referred to as context data.

In some examples, the contextual information that accompanies the user input includes sensor information, e.g., lighting, ambient noise, ambient temperature, images or videos of the surrounding environment, etc. In some examples, the contextual information can also include the physical state of the device, e.g., device orientation, device location, device temperature, power level, speed, acceleration, motion patterns, cellular signals strength, etc. In some examples, information related to the software state of DA server 106, e.g., running processes, installed programs, past and present network activities, background services, error logs, resources usage, etc., and of portable multifunction device 200 is provided to DA server 106 as contextual information associated with a user input.

In some examples, the digital assistant client module 229 selectively provides information (e.g., user data 231) stored on the portable multifunction device 200 in response to requests from DA server 106. In some examples, digital assistant client module 229 also elicits additional input from the user via a natural language dialogue or other user interfaces upon request by DA server 106. Digital assistant client module 229 passes the additional input to DA server 106 to help DA server 106 in intent deduction and/or fulfillment of the user's intent expressed in the user request.

A more detailed description of a digital assistant is described below with reference to FIGS. 7A-7C. It should be recognized that digital assistant client module 229 can include any number of the sub-modules of digital assistant module 726 described below.

Applications 236 include the following modules (or sets of instructions), or a subset or superset thereof:

-   -   Contacts module 237 (sometimes called an address book or contact         list);     -   Telephone module 238;     -   Video conference module 239;     -   E-mail client module 240;     -   Instant messaging (IM) module 241;     -   Workout support module 242;     -   Camera module 243 for still and/or video images;     -   Image management module 244;     -   Video player module;     -   Music player module;     -   Browser module 247;     -   Calendar module 248;     -   Widget modules 249, which includes, in some examples, one or         more of: weather widget 249-1, stocks widget 249-2, calculator         widget 249-3, alarm clock widget 249-4, dictionary widget 249-5,         and other widgets obtained by the user, as well as user-created         widgets 249-6;     -   Widget creator module 250 for making user-created widgets 249-6;     -   Search module 251;     -   Video and music player module 252, which merges video player         module and music player module;     -   Notes module 253;     -   Map module 254; and/or     -   Online video module 255.

Examples of other applications 236 that are stored in memory 202 include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication.

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, contacts module 237 are used to manage an address book or contact list (e.g., stored in application internal state 292 of contacts module 237 in memory 202 or memory 470), including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers or e-mail addresses to initiate and/or facilitate communications by telephone 238, video conference module 239, e-mail 240, or IM 241; and so forth.

In conjunction with RF circuitry 208, audio circuitry 210, speaker 211, microphone 213, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, telephone module 238 are used to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in contacts module 237, modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation, and disconnect or hang up when the conversation is completed. As noted above, the wireless communication uses any of a plurality of communications standards, protocols, and technologies.

In conjunction with RF circuitry 208, audio circuitry 210, speaker 211, microphone 213, touch screen 212, display controller 256, optical sensor 264, optical sensor controller 258, contact/motion module 230, graphics module 232, text input module 234, contacts module 237, and telephone module 238, video conference module 239 includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, e-mail client module 240 includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module 244, e-mail client module 240 makes it very easy to create and send e-mails with still or video images taken with camera module 243.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, the instant messaging module 241 includes executable instructions to enter a sequence of characters corresponding to an instant message, to modify previously entered characters, to transmit a respective instant message (for example, using a Short Message Service (SMS) or Multimedia Message Service (MIMS) protocol for telephony-based instant messages or using XMPP, SIMPLE, or IMPS for Internet-based instant messages), to receive instant messages, and to view received instant messages. In some embodiments, transmitted and/or received instant messages include graphics, photos, audio files, video files and/or other attachments as are supported in an MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XMPP, SIMPLE, or IMPS).

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, GPS module 235, map module 254, and music player module, workout support module 242 includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (sports devices); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store, and transmit workout data.

In conjunction with touch screen 212, display controller 256, optical sensor(s) 264, optical sensor controller 258, contact/motion module 230, graphics module 232, and image management module 244, camera module 243 includes executable instructions to capture still images or video (including a video stream) and store them into memory 202, modify characteristics of a still image or video, or delete a still image or video from memory 202.

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, and camera module 243, image management module 244 includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, browser module 247 includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, e-mail client module 240, and browser module 247, calendar module 248 includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to-do lists, etc.) in accordance with user instructions.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, and browser module 247, widget modules 249 are mini-applications that can be downloaded and used by a user (e.g., weather widget 249-1, stocks widget 249-2, calculator widget 249-3, alarm clock widget 249-4, and dictionary widget 249-5) or created by the user (e.g., user-created widget 249-6). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets).

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, and browser module 247, the widget creator module 250 are used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget).

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, search module 251 includes executable instructions to search for text, music, sound, image, video, and/or other files in memory 202 that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions.

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, audio circuitry 210, speaker 211, RF circuitry 208, and browser module 247, video and music player module 252 includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present, or otherwise play back videos (e.g., on touch screen 212 or on an external, connected display via external port 224). In some embodiments, device 200 optionally includes the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.).

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, and text input module 234, notes module 253 includes executable instructions to create and manage notes, to-do lists, and the like in accordance with user instructions.

In conjunction with RF circuitry 208, touch screen 212, display controller 256, contact/motion module 230, graphics module 232, text input module 234, GPS module 235, and browser module 247, map module 254 are used to receive, display, modify, and store maps and data associated with maps (e.g., driving directions, data on stores and other points of interest at or near a particular location, and other location-based data) in accordance with user instructions.

In conjunction with touch screen 212, display controller 256, contact/motion module 230, graphics module 232, audio circuitry 210, speaker 211, RF circuitry 208, text input module 234, e-mail client module 240, and browser module 247, online video module 255 includes instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display via external port 224), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module 241, rather than e-mail client module 240, is used to send a link to a particular online video. Additional description of the online video application can be found in U.S. Provisional Patent Application No. 60/936,562, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Jun. 20, 2007, and U.S. patent application Ser. No. 11/968,067, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Dec. 31, 2007, the contents of which are hereby incorporated by reference in their entirety.

Each of the above-identified modules and applications corresponds to a set of executable instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules can be combined or otherwise rearranged in various embodiments. For example, video player module can be combined with music player module into a single module (e.g., video and music player module 252, FIG. 2A). In some embodiments, memory 202 stores a subset of the modules and data structures identified above. Furthermore, memory 202 stores additional modules and data structures not described above.

In some embodiments, device 200 is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device 200, the number of physical input control devices (such as push buttons, dials, and the like) on device 200 is reduced.

The predefined set of functions that are performed exclusively through a touch screen and/or a touchpad optionally include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device 200 to a main, home, or root menu from any user interface that is displayed on device 200. In such embodiments, a “menu button” is implemented using a touchpad. In some other embodiments, the menu button is a physical push button or other physical input control device instead of a touchpad.

FIG. 2B is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory 202 (FIG. 2A) or 470 (FIG. 4) includes event sorter 270 (e.g., in operating system 226) and a respective application 236-1 (e.g., any of the aforementioned applications 237-251, 255, 480-490).

Event sorter 270 receives event information and determines the application 236-1 and application view 291 of application 236-1 to which to deliver the event information. Event sorter 270 includes event monitor 271 and event dispatcher module 274. In some embodiments, application 236-1 includes application internal state 292, which indicates the current application view(s) displayed on touch-sensitive display 212 when the application is active or executing. In some embodiments, device/global internal state 257 is used by event sorter 270 to determine which application(s) is (are) currently active, and application internal state 292 is used by event sorter 270 to determine application views 291 to which to deliver event information.

In some embodiments, application internal state 292 includes additional information, such as one or more of: resume information to be used when application 236-1 resumes execution, user interface state information that indicates information being displayed or that is ready for display by application 236-1, a state queue for enabling the user to go back to a prior state or view of application 236-1, and a redo/undo queue of previous actions taken by the user.

Event monitor 271 receives event information from peripherals interface 218. Event information includes information about a sub-event (e.g., a user touch on touch-sensitive display 212, as part of a multi-touch gesture). Peripherals interface 218 transmits information it receives from I/O subsystem 206 or a sensor, such as proximity sensor 266, accelerometer(s) 268, and/or microphone 213 (through audio circuitry 210). Information that peripherals interface 218 receives from I/O subsystem 206 includes information from touch-sensitive display 212 or a touch-sensitive surface.

In some embodiments, event monitor 271 sends requests to the peripherals interface 218 at predetermined intervals. In response, peripherals interface 218 transmits event information. In other embodiments, peripherals interface 218 transmits event information only when there is a significant event (e.g., receiving an input above a predetermined noise threshold and/or for more than a predetermined duration).

In some embodiments, event sorter 270 also includes a hit view determination module 272 and/or an active event recognizer determination module 273.

Hit view determination module 272 provides software procedures for determining where a sub-event has taken place within one or more views when touch-sensitive display 212 displays more than one view. Views are made up of controls and other elements that a user can see on the display.

Another aspect of the user interface associated with an application is a set of views, sometimes herein called application views or user interface windows, in which information is displayed and touch-based gestures occur. The application views (of a respective application) in which a touch is detected correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected is called the hit view, and the set of events that are recognized as proper inputs is determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture.

Hit view determination module 272 receives information related to sub events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module 272 identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (e.g., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module 272, the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view.

Active event recognizer determination module 273 determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module 273 determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module 273 determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views.

Event dispatcher module 274 dispatches the event information to an event recognizer (e.g., event recognizer 280). In embodiments including active event recognizer determination module 273, event dispatcher module 274 delivers the event information to an event recognizer determined by active event recognizer determination module 273. In some embodiments, event dispatcher module 274 stores in an event queue the event information, which is retrieved by a respective event receiver 282.

In some embodiments, operating system 226 includes event sorter 270. Alternatively, application 236-1 includes event sorter 270. In yet other embodiments, event sorter 270 is a stand-alone module, or a part of another module stored in memory 202, such as contact/motion module 230.

In some embodiments, application 236-1 includes a plurality of event handlers 290 and one or more application views 291, each of which includes instructions for handling touch events that occur within a respective view of the application's user interface. Each application view 291 of the application 236-1 includes one or more event recognizers 280. Typically, a respective application view 291 includes a plurality of event recognizers 280. In other embodiments, one or more of event recognizers 280 are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application 236-1 inherits methods and other properties. In some embodiments, a respective event handler 290 includes one or more of: data updater 276, object updater 277, GUI updater 278, and/or event data 279 received from event sorter 270. Event handler 290 utilizes or calls data updater 276, object updater 277, or GUI updater 278 to update the application internal state 292. Alternatively, one or more of the application views 291 include one or more respective event handlers 290. Also, in some embodiments, one or more of data updater 276, object updater 277, and GUI updater 278 are included in a respective application view 291.

A respective event recognizer 280 receives event information (e.g., event data 279) from event sorter 270 and identifies an event from the event information. Event recognizer 280 includes event receiver 282 and event comparator 284. In some embodiments, event recognizer 280 also includes at least a subset of: metadata 283, and event delivery instructions 288 (which include sub-event delivery instructions).

Event receiver 282 receives event information from event sorter 270. The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch, the event information also includes speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device.

Event comparator 284 compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator 284 includes event definitions 286. Event definitions 286 includes definitions of events (e.g., predefined sequences of sub-events), for example, event 1 (287-1), event 2 (287-2), and others. In some embodiments, sub-events in an event (287) include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event 1 (287-1) is a double tap on a displayed object. The double tap, for example, comprises a first touch (touch begin) on the displayed object for a predetermined phase, a first liftoff (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second liftoff (touch end) for a predetermined phase. In another example, the definition for event 2 (287-2) is a dragging on a displayed object. The dragging, for example, comprises a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch-sensitive display 212, and liftoff of the touch (touch end). In some embodiments, the event also includes information for one or more associated event handlers 290.

In some embodiments, event definition 287 includes a definition of an event for a respective user-interface object. In some embodiments, event comparator 284 performs a hit test to determine which user-interface object is associated with a sub-event. For example, in an application view in which three user-interface objects are displayed on touch-sensitive display 212, when a touch is detected on touch-sensitive display 212, event comparator 284 performs a hit test to determine which of the three user-interface objects is associated with the touch (sub-event). If each displayed object is associated with a respective event handler 290, the event comparator uses the result of the hit test to determine which event handler 290 should be activated. For example, event comparator 284 selects an event handler associated with the sub-event and the object triggering the hit test.

In some embodiments, the definition for a respective event (287) also includes delayed actions that delay delivery of the event information until after it has been determined whether the sequence of sub-events does or does not correspond to the event recognizer's event type.

When a respective event recognizer 280 determines that the series of sub-events do not match any of the events in event definitions 286, the respective event recognizer 280 enters an event impossible, event failed, or event ended state, after which it disregards subsequent sub-events of the touch-based gesture. In this situation, other event recognizers, if any, that remain active for the hit view continue to track and process sub-events of an ongoing touch-based gesture.

In some embodiments, a respective event recognizer 280 includes metadata 283 with configurable properties, flags, and/or lists that indicate how the event delivery system should perform sub-event delivery to actively involved event recognizers. In some embodiments, metadata 283 includes configurable properties, flags, and/or lists that indicate how event recognizers interact, or are enabled to interact, with one another. In some embodiments, metadata 283 includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy.

In some embodiments, a respective event recognizer 280 activates event handler 290 associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer 280 delivers event information associated with the event to event handler 290. Activating an event handler 290 is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer 280 throws a flag associated with the recognized event, and event handler 290 associated with the flag catches the flag and performs a predefined process.

In some embodiments, event delivery instructions 288 include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process.

In some embodiments, data updater 276 creates and updates data used in application 236-1. For example, data updater 276 updates the telephone number used in contacts module 237, or stores a video file used in video player module. In some embodiments, object updater 277 creates and updates objects used in application 236-1. For example, object updater 277 creates a new user-interface object or updates the position of a user-interface object. GUI updater 278 updates the GUI. For example, GUI updater 278 prepares display information and sends it to graphics module 232 for display on a touch-sensitive display.

In some embodiments, event handler(s) 290 includes or has access to data updater 276, object updater 277, and GUI updater 278. In some embodiments, data updater 276, object updater 277, and GUI updater 278 are included in a single module of a respective application 236-1 or application view 291. In other embodiments, they are included in two or more software modules.

It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices 200 with input devices, not all of which are initiated on touch screens. For example, mouse movement and mouse button presses, optionally coordinated with single or multiple keyboard presses or holds; contact movements such as taps, drags, scrolls, etc. on touchpads; pen stylus inputs; movement of the device; oral instructions; detected eye movements; biometric inputs; and/or any combination thereof are optionally utilized as inputs corresponding to sub-events which define an event to be recognized.

FIG. 3 illustrates a portable multifunction device 200 having a touch screen 212 in accordance with some embodiments. The touch screen optionally displays one or more graphics within user interface (UI) 300. In this embodiment, as well as others described below, a user is enabled to select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers 302 (not drawn to scale in the figure) or one or more styluses 303 (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture optionally includes one or more taps, one or more swipes (from left to right, right to left, upward and/or downward), and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device 200. In some implementations or circumstances, inadvertent contact with a graphic does not select the graphic. For example, a swipe gesture that sweeps over an application icon optionally does not select the corresponding application when the gesture corresponding to selection is a tap.

Device 200 also includes one or more physical buttons, such as “home” or menu button 304. As described previously, menu button 304 is used to navigate to any application 236 in a set of applications that is executed on device 200. Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen 212.

In one embodiment, device 200 includes touch screen 212, menu button 304, push button 306 for powering the device on/off and locking the device, volume adjustment button(s) 308, subscriber identity module (SIM) card slot 310, headset jack 312, and docking/charging external port 224. Push button 306 is, optionally, used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device 200 also accepts verbal input for activation or deactivation of some functions through microphone 213. Device 200 also, optionally, includes one or more contact intensity sensors 265 for detecting intensity of contacts on touch screen 212 and/or one or more tactile output generators 267 for generating tactile outputs for a user of device 200.

FIG. 4 is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. Device 400 need not be portable. In some embodiments, device 400 is a laptop computer, a desktop computer, a tablet computer, a multimedia player device, a navigation device, an educational device (such as a child's learning toy), a gaming system, or a control device (e.g., a home or industrial controller). Device 400 typically includes one or more processing units (CPUs) 410, one or more network or other communications interfaces 460, memory 470, and one or more communication buses 420 for interconnecting these components. Communication buses 420 optionally include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. Device 400 includes input/output (I/O) interface 430 comprising display 440, which is typically a touch screen display. I/O interface 430 also optionally includes a keyboard and/or mouse (or other pointing device) 450 and touchpad 455, tactile output generator 457 for generating tactile outputs on device 400 (e.g., similar to tactile output generator(s) 267 described above with reference to FIG. 2A), sensors 459 (e.g., optical, acceleration, proximity, touch-sensitive, and/or contact intensity sensors similar to contact intensity sensor(s) 265 described above with reference to FIG. 2A). Memory 470 includes high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices; and optionally includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory 470 optionally includes one or more storage devices remotely located from CPU(s) 410. In some embodiments, memory 470 stores programs, modules, and data structures analogous to the programs, modules, and data structures stored in memory 202 of portable multifunction device 200 (FIG. 2A), or a subset thereof. Furthermore, memory 470 optionally stores additional programs, modules, and data structures not present in memory 202 of portable multifunction device 200. For example, memory 470 of device 400 optionally stores drawing module 480, presentation module 482, word processing module 484, website creation module 486, disk authoring module 488, and/or spreadsheet module 490, while memory 202 of portable multifunction device 200 (FIG. 2A) optionally does not store these modules.

Each of the above-identified elements in FIG. 4 is, in some examples, stored in one or more of the previously mentioned memory devices. Each of the above-identified modules corresponds to a set of instructions for performing a function described above. The above-identified modules or programs (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules are combined or otherwise rearranged in various embodiments. In some embodiments, memory 470 stores a subset of the modules and data structures identified above. Furthermore, memory 470 stores additional modules and data structures not described above.

Attention is now directed towards embodiments of user interfaces that can be implemented on, for example, portable multifunction device 200.

FIG. 5A illustrates an exemplary user interface for a menu of applications on portable multifunction device 200 in accordance with some embodiments. Similar user interfaces are implemented on device 400. In some embodiments, user interface 500 includes the following elements, or a subset or superset thereof:

Signal strength indicator(s) 502 for wireless communication(s), such as cellular and Wi-Fi signals;

-   -   Time 504;     -   Bluetooth indicator 505;     -   Battery status indicator 506;     -   Tray 508 with icons for frequently used applications, such as:         -   Icon 516 for telephone module 238, labeled “Phone,” which             optionally includes an indicator 514 of the number of missed             calls or voicemail messages;         -   Icon 518 for e-mail client module 240, labeled “Mail,” which             optionally includes an indicator 510 of the number of unread             e-mails;         -   Icon 520 for browser module 247, labeled “Browser;” and         -   Icon 522 for video and music player module 252, also             referred to as iPod (trademark of Apple Inc.) module 252,             labeled “iPod;” and     -   Icons for other applications, such as:         -   Icon 524 for IM module 241, labeled “Messages;”         -   Icon 526 for calendar module 248, labeled “Calendar;”         -   Icon 528 for image management module 244, labeled “Photos;”         -   Icon 530 for camera module 243, labeled “Camera;”         -   Icon 532 for online video module 255, labeled “Online             Video;”         -   Icon 534 for stocks widget 249-2, labeled “Stocks;”         -   Icon 536 for map module 254, labeled “Maps;”         -   Icon 538 for weather widget 249-1, labeled “Weather;”         -   Icon 540 for alarm clock widget 249-4, labeled “Clock;”         -   Icon 542 for workout support module 242, labeled “Workout             Support;”         -   Icon 544 for notes module 253, labeled “Notes;” and         -   Icon 546 for a settings application or module, labeled             “Settings,” which provides access to settings for device 200             and its various applications 236.

It should be noted that the icon labels illustrated in FIG. 5A are merely exemplary. For example, icon 522 for video and music player module 252 is optionally labeled “Music” or “Music Player.” Other labels are, optionally, used for various application icons. In some embodiments, a label for a respective application icon includes a name of an application corresponding to the respective application icon. In some embodiments, a label for a particular application icon is distinct from a name of an application corresponding to the particular application icon.

FIG. 5B illustrates an exemplary user interface on a device (e.g., device 400, FIG. 4) with a touch-sensitive surface 551 (e.g., a tablet or touchpad 455, FIG. 4) that is separate from the display 550 (e.g., touch screen display 212). Device 400 also, optionally, includes one or more contact intensity sensors (e.g., one or more of sensors 459) for detecting intensity of contacts on touch-sensitive surface 551 and/or one or more tactile output generators 457 for generating tactile outputs for a user of device 400.

Although some of the examples which follow will be given with reference to inputs on touch screen display 212 (where the touch-sensitive surface and the display are combined), in some embodiments, the device detects inputs on a touch-sensitive surface that is separate from the display, as shown in FIG. 5B. In some embodiments, the touch-sensitive surface (e.g., 551 in FIG. 5B) has a primary axis (e.g., 552 in FIG. 5B) that corresponds to a primary axis (e.g., 553 in FIG. 5B) on the display (e.g., 550). In accordance with these embodiments, the device detects contacts (e.g., 560 and 562 in FIG. 5B) with the touch-sensitive surface 551 at locations that correspond to respective locations on the display (e.g., in FIG. 5B, 560 corresponds to 568 and 562 corresponds to 570). In this way, user inputs (e.g., contacts 560 and 562, and movements thereof) detected by the device on the touch-sensitive surface (e.g., 551 in FIG. 5B) are used by the device to manipulate the user interface on the display (e.g., 550 in FIG. 5B) of the multifunction device when the touch-sensitive surface is separate from the display. It should be understood that similar methods are, optionally, used for other user interfaces described herein.

Additionally, while the following examples are given primarily with reference to finger inputs (e.g., finger contacts, finger tap gestures, finger swipe gestures), it should be understood that, in some embodiments, one or more of the finger inputs are replaced with input from another input device (e.g., a mouse-based input or stylus input). For example, a swipe gesture is, optionally, replaced with a mouse click (e.g., instead of a contact) followed by movement of the cursor along the path of the swipe (e.g., instead of movement of the contact). As another example, a tap gesture is, optionally, replaced with a mouse click while the cursor is located over the location of the tap gesture (e.g., instead of detection of the contact followed by ceasing to detect the contact). Similarly, when multiple user inputs are simultaneously detected, it should be understood that multiple computer mice are, optionally, used simultaneously, or a mouse and finger contacts are, optionally, used simultaneously.

FIG. 6A illustrates exemplary personal electronic device 600. Device 600 includes body 602. In some embodiments, device 600 includes some or all of the features described with respect to devices 200 and 400 (e.g., FIGS. 2A-4). In some embodiments, device 600 has touch-sensitive display screen 604, hereafter touch screen 604. Alternatively, or in addition to touch screen 604, device 600 has a display and a touch-sensitive surface. As with devices 200 and 400, in some embodiments, touch screen 604 (or the touch-sensitive surface) has one or more intensity sensors for detecting intensity of contacts (e.g., touches) being applied. The one or more intensity sensors of touch screen 604 (or the touch-sensitive surface) provide output data that represents the intensity of touches. The user interface of device 600 responds to touches based on their intensity, meaning that touches of different intensities can invoke different user interface operations on device 600.

Techniques for detecting and processing touch intensity are found, for example, in related applications: International Patent Application Serial No. PCT/US2013/040061, titled “Device, Method, and Graphical User Interface for Displaying User Interface Objects Corresponding to an Application,” filed May 8, 2013, and International Patent Application Serial No. PCT/US2013/069483, titled “Device, Method, and Graphical User Interface for Transitioning Between Touch Input to Display Output Relationships,” filed Nov. 11, 2013, each of which is hereby incorporated by reference in their entirety.

In some embodiments, device 600 has one or more input mechanisms 606 and 608. Input mechanisms 606 and 608, if included, are physical. Examples of physical input mechanisms include push buttons and rotatable mechanisms. In some embodiments, device 600 has one or more attachment mechanisms. Such attachment mechanisms, if included, can permit attachment of device 600 with, for example, hats, eyewear, earrings, necklaces, shirts, jackets, bracelets, watch straps, chains, trousers, belts, shoes, purses, backpacks, and so forth. These attachment mechanisms permit device 600 to be worn by a user.

FIG. 6B depicts exemplary personal electronic device 600. In some embodiments, device 600 includes some or all of the components described with respect to FIGS. 2A, 2B, and 4. Device 600 has bus 612 that operatively couples I/O section 614 with one or more computer processors 616 and memory 618. I/O section 614 is connected to display 604, which can have touch-sensitive component 622 and, optionally, touch-intensity sensitive component 624. In addition, I/O section 614 is connected with communication unit 630 for receiving application and operating system data, using Wi-Fi, Bluetooth, near field communication (NFC), cellular, and/or other wireless communication techniques. Device 600 includes input mechanisms 606 and/or 608. Input mechanism 606 is a rotatable input device or a depressible and rotatable input device, for example. Input mechanism 608 is a button, in some examples.

Input mechanism 608 is a microphone, in some examples. Personal electronic device 600 includes, for example, various sensors, such as GPS sensor 632, accelerometer 634, directional sensor 640 (e.g., compass), gyroscope 636, motion sensor 638, and/or a combination thereof, all of which are operatively connected to I/O section 614.

Memory 618 of personal electronic device 600 is a non-transitory computer-readable storage medium, for storing computer-executable instructions, which, when executed by one or more computer processors 616, for example, cause the computer processors to perform the techniques and processes described below. The computer-executable instructions, for example, are also stored and/or transported within any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. Personal electronic device 600 is not limited to the components and configuration of FIG. 6B, but can include other or additional components in multiple configurations.

As used here, the term “affordance” refers to a user-interactive graphical user interface object that is, for example, displayed on the display screen of devices 200, 400, and/or 600 (FIGS. 2A, 4, and 6A-B). For example, an image (e.g., icon), a button, and text (e.g., hyperlink) each constitutes an affordance.

As used herein, the term “focus selector” refers to an input element that indicates a current part of a user interface with which a user is interacting. In some implementations that include a cursor or other location marker, the cursor acts as a “focus selector” so that when an input (e.g., a press input) is detected on a touch-sensitive surface (e.g., touchpad 455 in FIG. 4 or touch-sensitive surface 551 in FIG. 5B) while the cursor is over a particular user interface element (e.g., a button, window, slider or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations that include a touch screen display (e.g., touch-sensitive display system 212 in FIG. 2A or touch screen 212 in FIG. 5A) that enables direct interaction with user interface elements on the touch screen display, a detected contact on the touch screen acts as a “focus selector” so that when an input (e.g., a press input by the contact) is detected on the touch screen display at a location of a particular user interface element (e.g., a button, window, slider, or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations, focus is moved from one region of a user interface to another region of the user interface without corresponding movement of a cursor or movement of a contact on a touch screen display (e.g., by using a tab key or arrow keys to move focus from one button to another button); in these implementations, the focus selector moves in accordance with movement of focus between different regions of the user interface. Without regard to the specific form taken by the focus selector, the focus selector is generally the user interface element (or contact on a touch screen display) that is controlled by the user so as to communicate the user's intended interaction with the user interface (e.g., by indicating, to the device, the element of the user interface with which the user is intending to interact). For example, the location of a focus selector (e.g., a cursor, a contact, or a selection box) over a respective button while a press input is detected on the touch-sensitive surface (e.g., a touchpad or touch screen) will indicate that the user is intending to activate the respective button (as opposed to other user interface elements shown on a display of the device).

As used in the specification and claims, the term “characteristic intensity” of a contact refers to a characteristic of the contact based on one or more intensities of the contact. In some embodiments, the characteristic intensity is based on multiple intensity samples. The characteristic intensity is, optionally, based on a predefined number of intensity samples, or a set of intensity samples collected during a predetermined time period (e.g., 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10 seconds) relative to a predefined event (e.g., after detecting the contact, prior to detecting liftoff of the contact, before or after detecting a start of movement of the contact, prior to detecting an end of the contact, before or after detecting an increase in intensity of the contact, and/or before or after detecting a decrease in intensity of the contact). A characteristic intensity of a contact is, optionally based on one or more of: a maximum value of the intensities of the contact, a mean value of the intensities of the contact, an average value of the intensities of the contact, a top 10 percentile value of the intensities of the contact, a value at the half maximum of the intensities of the contact, a value at the 90 percent maximum of the intensities of the contact, or the like. In some embodiments, the duration of the contact is used in determining the characteristic intensity (e.g., when the characteristic intensity is an average of the intensity of the contact over time). In some embodiments, the characteristic intensity is compared to a set of one or more intensity thresholds to determine whether an operation has been performed by a user. For example, the set of one or more intensity thresholds includes a first intensity threshold and a second intensity threshold. In this example, a contact with a characteristic intensity that does not exceed the first threshold results in a first operation, a contact with a characteristic intensity that exceeds the first intensity threshold and does not exceed the second intensity threshold results in a second operation, and a contact with a characteristic intensity that exceeds the second threshold results in a third operation. In some embodiments, a comparison between the characteristic intensity and one or more thresholds is used to determine whether or not to perform one or more operations (e.g., whether to perform a respective operation or forgo performing the respective operation) rather than being used to determine whether to perform a first operation or a second operation.

In some embodiments, a portion of a gesture is identified for purposes of determining a characteristic intensity. For example, a touch-sensitive surface receives a continuous swipe contact transitioning from a start location and reaching an end location, at which point the intensity of the contact increases. In this example, the characteristic intensity of the contact at the end location is based on only a portion of the continuous swipe contact, and not the entire swipe contact (e.g., only the portion of the swipe contact at the end location). In some embodiments, a smoothing algorithm is applied to the intensities of the swipe contact prior to determining the characteristic intensity of the contact. For example, the smoothing algorithm optionally includes one or more of: an unweighted sliding-average smoothing algorithm, a triangular smoothing algorithm, a median filter smoothing algorithm, and/or an exponential smoothing algorithm. In some circumstances, these smoothing algorithms eliminate narrow spikes or dips in the intensities of the swipe contact for purposes of determining a characteristic intensity.

The intensity of a contact on the touch-sensitive surface is characterized relative to one or more intensity thresholds, such as a contact-detection intensity threshold, a light press intensity threshold, a deep press intensity threshold, and/or one or more other intensity thresholds. In some embodiments, the light press intensity threshold corresponds to an intensity at which the device will perform operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, the deep press intensity threshold corresponds to an intensity at which the device will perform operations that are different from operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, when a contact is detected with a characteristic intensity below the light press intensity threshold (e.g., and above a nominal contact-detection intensity threshold below which the contact is no longer detected), the device will move a focus selector in accordance with movement of the contact on the touch-sensitive surface without performing an operation associated with the light press intensity threshold or the deep press intensity threshold. Generally, unless otherwise stated, these intensity thresholds are consistent between different sets of user interface figures.

An increase of characteristic intensity of the contact from an intensity below the light press intensity threshold to an intensity between the light press intensity threshold and the deep press intensity threshold is sometimes referred to as a “light press” input. An increase of characteristic intensity of the contact from an intensity below the deep press intensity threshold to an intensity above the deep press intensity threshold is sometimes referred to as a “deep press” input. An increase of characteristic intensity of the contact from an intensity below the contact-detection intensity threshold to an intensity between the contact-detection intensity threshold and the light press intensity threshold is sometimes referred to as detecting the contact on the touch-surface. A decrease of characteristic intensity of the contact from an intensity above the contact-detection intensity threshold to an intensity below the contact-detection intensity threshold is sometimes referred to as detecting liftoff of the contact from the touch-surface. In some embodiments, the contact-detection intensity threshold is zero. In some embodiments, the contact-detection intensity threshold is greater than zero.

In some embodiments described herein, one or more operations are performed in response to detecting a gesture that includes a respective press input or in response to detecting the respective press input performed with a respective contact (or a plurality of contacts), where the respective press input is detected based at least in part on detecting an increase in intensity of the contact (or plurality of contacts) above a press-input intensity threshold. In some embodiments, the respective operation is performed in response to detecting the increase in intensity of the respective contact above the press-input intensity threshold (e.g., a “down stroke” of the respective press input). In some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the press-input threshold (e.g., an “up stroke” of the respective press input).

In some embodiments, the device employs intensity hysteresis to avoid accidental inputs sometimes termed “jitter,” where the device defines or selects a hysteresis intensity threshold with a predefined relationship to the press-input intensity threshold (e.g., the hysteresis intensity threshold is X intensity units lower than the press-input intensity threshold or the hysteresis intensity threshold is 75%, 90%, or some reasonable proportion of the press-input intensity threshold). Thus, in some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the hysteresis intensity threshold that corresponds to the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the hysteresis intensity threshold (e.g., an “up stroke” of the respective press input). Similarly, in some embodiments, the press input is detected only when the device detects an increase in intensity of the contact from an intensity at or below the hysteresis intensity threshold to an intensity at or above the press-input intensity threshold and, optionally, a subsequent decrease in intensity of the contact to an intensity at or below the hysteresis intensity, and the respective operation is performed in response to detecting the press input (e.g., the increase in intensity of the contact or the decrease in intensity of the contact, depending on the circumstances).

For ease of explanation, the descriptions of operations performed in response to a press input associated with a press-input intensity threshold or in response to a gesture including the press input are, optionally, triggered in response to detecting either: an increase in intensity of a contact above the press-input intensity threshold, an increase in intensity of a contact from an intensity below the hysteresis intensity threshold to an intensity above the press-input intensity threshold, a decrease in intensity of the contact below the press-input intensity threshold, and/or a decrease in intensity of the contact below the hysteresis intensity threshold corresponding to the press-input intensity threshold. Additionally, in examples where an operation is described as being performed in response to detecting a decrease in intensity of a contact below the press-input intensity threshold, the operation is, optionally, performed in response to detecting a decrease in intensity of the contact below a hysteresis intensity threshold corresponding to, and lower than, the press-input intensity threshold.

3. Digital Assistant System

FIG. 7A illustrates a block diagram of digital assistant system 700 in accordance with various examples. In some examples, digital assistant system 700 is implemented on a standalone computer system. In some examples, digital assistant system 700 is distributed across multiple computers. In some examples, some of the modules and functions of the digital assistant are divided into a server portion and a client portion, where the client portion resides on one or more user devices (e.g., devices 104, 122, 200, 400, or 600) and communicates with the server portion (e.g., server system 108) through one or more networks, e.g., as shown in FIG. 1. In some examples, digital assistant system 700 is an implementation of server system 108 (and/or DA server 106) shown in FIG. 1. It should be noted that digital assistant system 700 is only one example of a digital assistant system, and that digital assistant system 700 can have more or fewer components than shown, can combine two or more components, or can have a different configuration or arrangement of the components. The various components shown in FIG. 7A are implemented in hardware, software instructions for execution by one or more processors, firmware, including one or more signal processing and/or application specific integrated circuits, or a combination thereof.

Digital assistant system 700 includes memory 702, one or more processors 704, input/output (I/O) interface 706, and network communications interface 708. These components can communicate with one another over one or more communication buses or signal lines 710.

In some examples, memory 702 includes a non-transitory computer-readable medium, such as high-speed random access memory and/or a non-volatile computer-readable storage medium (e.g., one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices).

In some examples, I/O interface 706 couples input/output devices 716 of digital assistant system 700, such as displays, keyboards, touch screens, and microphones, to user interface module 722. I/O interface 706, in conjunction with user interface module 722, receives user inputs (e.g., voice input, keyboard inputs, touch inputs, etc.) and processes them accordingly. In some examples, e.g., when the digital assistant is implemented on a standalone user device, digital assistant system 700 includes any of the components and I/O communication interfaces described with respect to devices 200, 400, or 600 in FIGS. 2A, 4, and 6A-6B, respectively. In some examples, digital assistant system 700 represents the server portion of a digital assistant implementation, and can interact with the user through a client-side portion residing on a user device (e.g., devices 104, 200, 400, or 600).

In some examples, the network communications interface 708 includes wired communication port(s) 712 and/or wireless transmission and reception circuitry 714. The wired communication port(s) receives and send communication signals via one or more wired interfaces, e.g., Ethernet, Universal Serial Bus (USB), FIREWIRE, etc. The wireless circuitry 714 receives and sends RF signals and/or optical signals from/to communications networks and other communications devices. The wireless communications use any of a plurality of communications standards, protocols, and technologies, such as GSM, EDGE, CDMA, TDMA, Bluetooth, Wi-Fi, VoIP, Wi-MAX, or any other suitable communication protocol. Network communications interface 708 enables communication between digital assistant system 700 with networks, such as the Internet, an intranet, and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN), and/or a metropolitan area network (MAN), and other devices.

In some examples, memory 702, or the computer-readable storage media of memory 702, stores programs, modules, instructions, and data structures including all or a subset of: operating system 718, communications module 720, user interface module 722, one or more applications 724, and digital assistant module 726. In particular, memory 702, or the computer-readable storage media of memory 702, stores instructions for performing the processes described below. One or more processors 704 execute these programs, modules, and instructions, and reads/writes from/to the data structures.

Operating system 718 (e.g., Darwin, RTXC, LINUX, UNIX, iOS, OS X, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communications between various hardware, firmware, and software components.

Communications module 720 facilitates communications between digital assistant system 700 with other devices over network communications interface 708. For example, communications module 720 communicates with RF circuitry 208 of electronic devices such as devices 200, 400, and 600 shown in FIGS. 2A, 4, 6A-6B, respectively. Communications module 720 also includes various components for handling data received by wireless circuitry 714 and/or wired communications port 712.

User interface module 722 receives commands and/or inputs from a user via I/O interface 706 (e.g., from a keyboard, touch screen, pointing device, controller, and/or microphone), and generate user interface objects on a display. User interface module 722 also prepares and delivers outputs (e.g., speech, sound, animation, text, icons, vibrations, haptic feedback, light, etc.) to the user via the I/O interface 706 (e.g., through displays, audio channels, speakers, touch-pads, etc.).

Applications 724 include programs and/or modules that are configured to be executed by one or more processors 704. For example, if the digital assistant system is implemented on a standalone user device, applications 724 include user applications, such as games, a calendar application, a navigation application, or an email application. If digital assistant system 700 is implemented on a server, applications 724 include resource management applications, diagnostic applications, or scheduling applications, for example.

Memory 702 also stores digital assistant module 726 (or the server portion of a digital assistant). In some examples, digital assistant module 726 includes the following sub-modules, or a subset or superset thereof: input/output processing module 728, speech-to-text (STT) processing module 730, natural language processing module 732, dialogue flow processing module 734, task flow processing module 736, service processing module 738, and speech synthesis processing module 740. Each of these modules has access to one or more of the following systems or data and models of the digital assistant module 726, or a subset or superset thereof: ontology 760, vocabulary index 744, user data 748, task flow models 754, service models 756, and ASR systems 758.

In some examples, using the processing modules, data, and models implemented in digital assistant module 726, the digital assistant can perform at least some of the following: converting speech input into text; identifying a user's intent expressed in a natural language input received from the user; actively eliciting and obtaining information needed to fully infer the user's intent (e.g., by disambiguating words, games, intentions, etc.); determining the task flow for fulfilling the inferred intent; and executing the task flow to fulfill the inferred intent.

In some examples, as shown in FIG. 7B, I/O processing module 728 interacts with the user through I/O devices 716 in FIG. 7A or with a user device (e.g., devices 104, 200, 400, or 600) through network communications interface 708 in FIG. 7A to obtain user input (e.g., a speech input) and to provide responses (e.g., as speech outputs) to the user input. I/O processing module 728 optionally obtains contextual information associated with the user input from the user device, along with or shortly after the receipt of the user input. The contextual information includes user-specific data, vocabulary, and/or preferences relevant to the user input. In some examples, the contextual information also includes software and hardware states of the user device at the time the user request is received, and/or information related to the surrounding environment of the user at the time that the user request was received. In some examples, I/O processing module 728 also sends follow-up questions to, and receive answers from, the user regarding the user request. When a user request is received by I/O processing module 728 and the user request includes speech input, I/O processing module 728 forwards the speech input to STT processing module 730 (or speech recognizer) for speech-to-text conversions.

STT processing module 730 includes one or more ASR systems 758. The one or more ASR systems 758 can process the speech input that is received through I/O processing module 728 to produce a recognition result. Each ASR system 758 includes a front-end speech pre-processor. The front-end speech pre-processor extracts representative features from the speech input. For example, the front-end speech pre-processor performs a Fourier transform on the speech input to extract spectral features that characterize the speech input as a sequence of representative multi-dimensional vectors. Further, each ASR system 758 includes one or more speech recognition models (e.g., acoustic models and/or language models) and implements one or more speech recognition engines. Examples of speech recognition models include Hidden Markov Models, Gaussian-Mixture Models, Deep Neural Network Models, n-gram language models, and other statistical models. Examples of speech recognition engines include the dynamic time warping based engines and weighted finite-state transducers (WFST) based engines. The one or more speech recognition models and the one or more speech recognition engines are used to process the extracted representative features of the front-end speech pre-processor to produce intermediate recognitions results (e.g., phonemes, phonemic strings, and sub-words), and ultimately, text recognition results (e.g., words, word strings, or sequence of tokens). In some examples, the speech input is processed at least partially by a third-party service or on the user's device (e.g., device 104, 200, 400, or 600) to produce the recognition result. Once STT processing module 730 produces recognition results including a text string (e.g., words, or sequence of words, or sequence of tokens), the recognition result is passed to natural language processing module 732 for intent deduction. In some examples, STT processing module 730 produces multiple candidate text representations of the speech input. Each candidate text representation is a sequence of words or tokens corresponding to the speech input. In some examples, each candidate text representation is associated with a speech recognition confidence score. Based on the speech recognition confidence scores, STT processing module 730 ranks the candidate text representations and provides the n-best (e.g., n highest ranked) candidate text representation(s) to natural language processing module 732 for intent deduction, where n is a predetermined integer greater than zero. For example, in one example, only the highest ranked (n=1) candidate text representation is passed to natural language processing module 732 for intent deduction. In another example, the five highest ranked (n=5) candidate text representations are passed to natural language processing module 732 for intent deduction.

More details on the speech-to-text processing are described in U.S. Utility application Ser. No. 13/236,942 for “Consolidating Speech Recognition Results,” filed on Sep. 20, 2011, the entire disclosure of which is incorporated herein by reference.

In some examples, STT processing module 730 includes and/or accesses a vocabulary of recognizable words via phonetic alphabet conversion module 731. Each vocabulary word is associated with one or more candidate pronunciations of the word represented in a speech recognition phonetic alphabet. In particular, the vocabulary of recognizable words includes a word that is associated with a plurality of candidate pronunciations. For example, the vocabulary includes the word “tomato” that is associated with the candidate pronunciations of /

/ and /

/. Further, vocabulary words are associated with custom candidate pronunciations that are based on previous speech inputs from the user. Such custom candidate pronunciations are stored in STT processing module 730 and are associated with a particular user via the user's profile on the device. In some examples, the candidate pronunciations for words are determined based on the spelling of the word and one or more linguistic and/or phonetic rules. In some examples, the candidate pronunciations are manually generated, e.g., based on known canonical pronunciations.

In some examples, the candidate pronunciations are ranked based on the commonness of the candidate pronunciation. For example, the candidate pronunciation /

/ is ranked higher than /

/, because the former is a more commonly used pronunciation (e.g., among all users, for users in a particular geographical region, or for any other appropriate subset of users). In some examples, candidate pronunciations are ranked based on whether the candidate pronunciation is a custom candidate pronunciation associated with the user. For example, custom candidate pronunciations are ranked higher than canonical candidate pronunciations. This can be useful for recognizing proper nouns having a unique pronunciation that deviates from canonical pronunciation. In some examples, candidate pronunciations are associated with one or more speech characteristics, such as geographic origin, nationality, or ethnicity. For example, the candidate pronunciation /

/ is associated with the United States, whereas the candidate pronunciation /

/ is associated with Great Britain. Further, the rank of the candidate pronunciation is based on one or more characteristics (e.g., geographic origin, nationality, ethnicity, etc.) of the user stored in the user's profile on the device. For example, it can be determined from the user's profile that the user is associated with the United States. Based on the user being associated with the United States, the candidate pronunciation /

/ (associated with the United States) is ranked higher than the candidate pronunciation /

/ (associated with Great Britain). In some examples, one of the ranked candidate pronunciations is selected as a predicted pronunciation (e.g., the most likely pronunciation).

When a speech input is received, STT processing module 730 is used to determine the phonemes corresponding to the speech input (e.g., using an acoustic model), and then attempt to determine words that match the phonemes (e.g., using a language model). For example, if STT processing module 730 first identifies the sequence of phonemes /

/ corresponding to a portion of the speech input, it can then determine, based on vocabulary index 744, that this sequence corresponds to the word “tomato.”

In some examples, STT processing module 730 uses approximate matching techniques to determine words in an utterance. Thus, for example, the STT processing module 730 determines that the sequence of phonemes /

/ corresponds to the word “tomato,” even if that particular sequence of phonemes is not one of the candidate sequence of phonemes for that word.

Natural language processing module 732 (“natural language processor”) of the digital assistant takes the n-best candidate text representation(s) (“word sequence(s)” or “token sequence(s)”) generated by STT processing module 730, and attempts to associate each of the candidate text representations with one or more “actionable intents” recognized by the digital assistant. An “actionable intent” (or “user intent”) represents a task that can be performed by the digital assistant, and can have an associated task flow implemented in task flow models 754. The associated task flow is a series of programmed actions and steps that the digital assistant takes in order to perform the task. The scope of a digital assistant's capabilities is dependent on the number and variety of task flows that have been implemented and stored in task flow models 754, or in other words, on the number and variety of “actionable intents” that the digital assistant recognizes. The effectiveness of the digital assistant, however, also dependents on the assistant's ability to infer the correct “actionable intent(s)” from the user request expressed in natural language.

In some examples, in addition to the sequence of words or tokens obtained from STT processing module 730, natural language processing module 732 also receives contextual information associated with the user request, e.g., from I/O processing module 728. The natural language processing module 732 optionally uses the contextual information to clarify, supplement, and/or further define the information included in the candidate text representations received from STT processing module 730. The contextual information includes, for example, user preferences, hardware, and/or software states of the user device, sensor information collected before, during, or shortly after the user request, prior interactions (e.g., dialogue) between the digital assistant and the user, and the like. As described herein, contextual information is, in some examples, dynamic, and changes with time, location, content of the dialogue, and other factors.

In some examples, the natural language processing is based on, e.g., ontology 760.

Ontology 760 is a hierarchical structure including many nodes, each node representing either an “actionable intent” or a “property” relevant to one or more of the “actionable intents” or other “properties.” As noted above, an “actionable intent” represents a task that the digital assistant is capable of performing, i.e., it is “actionable” or can be acted on. A “property” represents a parameter associated with an actionable intent or a sub-aspect of another property. A linkage between an actionable intent node and a property node in ontology 760 defines how a parameter represented by the property node pertains to the task represented by the actionable intent node.

In some examples, ontology 760 is made up of actionable intent nodes and property nodes. Within ontology 760, each actionable intent node is linked to one or more property nodes either directly or through one or more intermediate property nodes. Similarly, each property node is linked to one or more actionable intent nodes either directly or through one or more intermediate property nodes. For example, as shown in FIG. 7C, ontology 760 includes a “restaurant reservation” node (i.e., an actionable intent node). Property nodes “restaurant,” “date/time” (for the reservation), and “party size” are each directly linked to the actionable intent node (i.e., the “restaurant reservation” node).

In addition, property nodes “cuisine,” “price range,” “phone number,” and “location” are sub-nodes of the property node “restaurant,” and are each linked to the “restaurant reservation” node (i.e., the actionable intent node) through the intermediate property node “restaurant.” For another example, as shown in FIG. 7C, ontology 760 also includes a “set reminder” node (i.e., another actionable intent node). Property nodes “date/time” (for setting the reminder) and “subject” (for the reminder) are each linked to the “set reminder” node. Since the property “date/time” is relevant to both the task of making a restaurant reservation and the task of setting a reminder, the property node “date/time” is linked to both the “restaurant reservation” node and the “set reminder” node in ontology 760.

An actionable intent node, along with its linked property nodes, is described as a “domain.” In the present discussion, each domain is associated with a respective actionable intent, and refers to the group of nodes (and the relationships there between) associated with the particular actionable intent. For example, ontology 760 shown in FIG. 7C includes an example of restaurant reservation domain 762 and an example of reminder domain 764 within ontology 760. The restaurant reservation domain includes the actionable intent node “restaurant reservation,” property nodes “restaurant,” “date/time,” and “party size,” and sub-property nodes “cuisine,” “price range,” “phone number,” and “location.” Reminder domain 764 includes the actionable intent node “set reminder,” and property nodes “subject” and “date/time.” In some examples, ontology 760 is made up of many domains. Each domain shares one or more property nodes with one or more other domains. For example, the “date/time” property node is associated with many different domains (e.g., a scheduling domain, a travel reservation domain, a movie ticket domain, etc.), in addition to restaurant reservation domain 762 and reminder domain 764.

While FIG. 7C illustrates two example domains within ontology 760, other domains include, for example, “find a movie,” “initiate a phone call,” “find directions,” “schedule a meeting,” “send a message,” and “provide an answer to a question,” “read a list,” “providing navigation instructions,” “provide instructions for a task” and so on. A “send a message” domain is associated with a “send a message” actionable intent node, and further includes property nodes such as “recipient(s),” “message type,” and “message body.” The property node “recipient” is further defined, for example, by the sub-property nodes such as “recipient name” and “message address.”

In some examples, ontology 760 includes all the domains (and hence actionable intents) that the digital assistant is capable of understanding and acting upon. In some examples, ontology 760 is modified, such as by adding or removing entire domains or nodes, or by modifying relationships between the nodes within the ontology 760.

In some examples, nodes associated with multiple related actionable intents are clustered under a “super domain” in ontology 760. For example, a “travel” super-domain includes a cluster of property nodes and actionable intent nodes related to travel. The actionable intent nodes related to travel includes “airline reservation,” “hotel reservation,” “car rental,” “get directions,” “find points of interest,” and so on. The actionable intent nodes under the same super domain (e.g., the “travel” super domain) have many property nodes in common. For example, the actionable intent nodes for “airline reservation,” “hotel reservation,” “car rental,” “get directions,” and “find points of interest” share one or more of the property nodes “start location,” “destination,” “departure date/time,” “arrival date/time,” and “party size.”

In some examples, each node in ontology 760 is associated with a set of words and/or phrases that are relevant to the property or actionable intent represented by the node. The respective set of words and/or phrases associated with each node are the so-called “vocabulary” associated with the node. The respective set of words and/or phrases associated with each node are stored in vocabulary index 744 in association with the property or actionable intent represented by the node. For example, returning to FIG. 7B, the vocabulary associated with the node for the property of “restaurant” includes words such as “food,” “drinks,” “cuisine,” “hungry,” “eat,” “pizza,” “fast food,” “meal,” and so on. For another example, the vocabulary associated with the node for the actionable intent of “initiate a phone call” includes words and phrases such as “call,” “phone,” “dial,” “ring,” “call this number,” “make a call to,” and so on. The vocabulary index 744 optionally includes words and phrases in different languages.

Natural language processing module 732 receives the candidate text representations (e.g., text string(s) or token sequence(s)) from STT processing module 730, and for each candidate representation, determines what nodes are implicated by the words in the candidate text representation. In some examples, if a word or phrase in the candidate text representation is found to be associated with one or more nodes in ontology 760 (via vocabulary index 744), the word or phrase “triggers” or “activates” those nodes. Based on the quantity and/or relative importance of the activated nodes, natural language processing module 732 selects one of the actionable intents as the task that the user intended the digital assistant to perform. In some examples, the domain that has the most “triggered” nodes is selected. In some examples, the domain having the highest confidence value (e.g., based on the relative importance of its various triggered nodes) is selected. In some examples, the domain is selected based on a combination of the number and the importance of the triggered nodes. In some examples, additional factors are considered in selecting the node as well, such as whether the digital assistant has previously correctly interpreted a similar request from a user.

User data 748 includes user-specific information, such as user-specific vocabulary, user preferences, user address, user's default and secondary languages, user's contact list, and other short-term or long-term information for each user. In some examples, natural language processing module 732 uses the user-specific information to supplement the information included in the user input to further define the user intent. For example, for a user request “invite my friends to my birthday party,” natural language processing module 732 is able to access user data 748 to determine who the “friends” are and when and where the “birthday party” would be held, rather than requiring the user to provide such information explicitly in his/her request.

It should be recognized that in some examples, natural language processing module 732 is implemented using one or more machine learning mechanisms (e.g., neural networks). In particular, the one or more machine learning mechanisms are configured to receive a candidate text representation and contextual information associated with the candidate text representation. Based on the candidate text representation and the associated contextual information, the one or more machine learning mechanisms are configured to determine intent confidence scores over a set of candidate actionable intents. Natural language processing module 732 can select one or more candidate actionable intents from the set of candidate actionable intents based on the determined intent confidence scores. In some examples, an ontology (e.g., ontology 760) is also used to select the one or more candidate actionable intents from the set of candidate actionable intents.

Other details of searching an ontology based on a token string are described in U.S. Utility application Ser. No. 12/341,743 for “Method and Apparatus for Searching Using An Active Ontology,” filed Dec. 22, 2008, the entire disclosure of which is incorporated herein by reference.

In some examples, once natural language processing module 732 identifies an actionable intent (or domain) based on the user request, natural language processing module 732 generates a structured query to represent the identified actionable intent. In some examples, the structured query includes parameters for one or more nodes within the domain for the actionable intent, and at least some of the parameters are populated with the specific information and requirements specified in the user request. For example, the user says “Make me a dinner reservation at a sushi place at 7.” In this case, natural language processing module 732 is able to correctly identify the actionable intent to be “restaurant reservation” based on the user input. According to the ontology, a structured query for a “restaurant reservation” domain includes parameters such as {Cuisine}, {Time}, {Date}, {Party Size}, and the like. In some examples, based on the speech input and the text derived from the speech input using STT processing module 730, natural language processing module 732 generates a partial structured query for the restaurant reservation domain, where the partial structured query includes the parameters {Cuisine=“Sushi”} and {Time=“7 pm”}. However, in this example, the user's utterance includes insufficient information to complete the structured query associated with the domain. Therefore, other necessary parameters such as {Party Size} and {Date} are not specified in the structured query based on the information currently available. In some examples, natural language processing module 732 populates some parameters of the structured query with received contextual information. For example, in some examples, if the user requested a sushi restaurant “near me,” natural language processing module 732 populates a {location} parameter in the structured query with GPS coordinates from the user device.

In some examples, natural language processing module 732 identifies multiple candidate actionable intents for each candidate text representation received from STT processing module 730. Further, in some examples, a respective structured query (partial or complete) is generated for each identified candidate actionable intent. Natural language processing module 732 determines an intent confidence score for each candidate actionable intent and ranks the candidate actionable intents based on the intent confidence scores. In some examples, natural language processing module 732 passes the generated structured query (or queries), including any completed parameters, to task flow processing module 736 (“task flow processor”). In some examples, the structured query (or queries) for the m-best (e.g., m highest ranked) candidate actionable intents are provided to task flow processing module 736, where m is a predetermined integer greater than zero. In some examples, the structured query (or queries) for the m-best candidate actionable intents are provided to task flow processing module 736 with the corresponding candidate text representation(s).

Other details of inferring a user intent based on multiple candidate actionable intents determined from multiple candidate text representations of a speech input are described in U.S. Utility application Ser. No. 14/298,725 for “System and Method for Inferring User Intent From Speech Inputs,” filed Jun. 6, 2014, the entire disclosure of which is incorporated herein by reference.

Task flow processing module 736 is configured to receive the structured query (or queries) from natural language processing module 732, complete the structured query, if necessary, and perform the actions required to “complete” the user's ultimate request. In some examples, the various procedures necessary to complete these tasks are provided in task flow models 754. In some examples, task flow models 754 include procedures for obtaining additional information from the user and task flows for performing actions associated with the actionable intent.

As described above, in order to complete a structured query, task flow processing module 736 needs to initiate additional dialogue with the user in order to obtain additional information, and/or disambiguate potentially ambiguous utterances. When such interactions are necessary, task flow processing module 736 invokes dialogue flow processing module 734 to engage in a dialogue with the user. In some examples, dialogue flow processing module 734 determines how (and/or when) to ask the user for the additional information and receives and processes the user responses. The questions are provided to and answers are received from the users through I/O processing module 728. In some examples, dialogue flow processing module 734 presents dialogue output to the user via audio and/or visual output, and receives input from the user via spoken or physical (e.g., clicking) responses. Continuing with the example above, when task flow processing module 736 invokes dialogue flow processing module 734 to determine the “party size” and “date” information for the structured query associated with the domain “restaurant reservation,” dialogue flow processing module 734 generates questions such as “For how many people?” and “On which day?” to pass to the user. Once answers are received from the user, dialogue flow processing module 734 then populates the structured query with the missing information, or pass the information to task flow processing module 736 to complete the missing information from the structured query.

Once task flow processing module 736 has completed the structured query for an actionable intent, task flow processing module 736 proceeds to perform the ultimate task associated with the actionable intent. Accordingly, task flow processing module 736 executes the steps and instructions in the task flow model according to the specific parameters included in the structured query. For example, the task flow model for the actionable intent of “restaurant reservation” includes steps and instructions for contacting a restaurant and actually requesting a reservation for a particular party size at a particular time. For example, using a structured query such as: {restaurant reservation, restaurant=ABC Café, date=Mar. 12, 2012, time=7 pm, party size=5}, task flow processing module 736 performs the steps of: (1) logging onto a server of the ABC Café or a restaurant reservation system such as OPENTABLE®, (2) entering the date, time, and party size information in a form on the website, (3) submitting the form, and (4) making a calendar entry for the reservation in the user's calendar.

In some examples, task flow processing module 736 employs the assistance of service processing module 738 (“service processing module”) to complete a task requested in the user input or to provide an informational answer requested in the user input. For example, service processing module 738 acts on behalf of task flow processing module 736 to make a phone call, set a calendar entry, invoke a map search, invoke or interact with other user applications installed on the user device, and invoke or interact with third-party services (e.g., a restaurant reservation portal, a social networking website, a banking portal, etc.). In some examples, the protocols and application programming interfaces (API) required by each service are specified by a respective service model among service models 756. Service processing module 738 accesses the appropriate service model for a service and generates requests for the service in accordance with the protocols and APIs required by the service according to the service model.

For example, if a restaurant has enabled an online reservation service, the restaurant submits a service model specifying the necessary parameters for making a reservation and the APIs for communicating the values of the necessary parameter to the online reservation service. When requested by task flow processing module 736, service processing module 738 establishes a network connection with the online reservation service using the web address stored in the service model, and sends the necessary parameters of the reservation (e.g., time, date, party size) to the online reservation interface in a format according to the API of the online reservation service.

In some examples, natural language processing module 732, dialogue flow processing module 734, and task flow processing module 736 are used collectively and iteratively to infer and define the user's intent, obtain information to further clarify and refine the user intent, and finally generate a response (i.e., an output to the user, or the completion of a task) to fulfill the user's intent. The generated response is a dialogue response to the speech input that at least partially fulfills the user's intent. Further, in some examples, the generated response is output as a speech output. In these examples, the generated response is sent to speech synthesis processing module 740 (e.g., speech synthesizer) where it can be processed to synthesize the dialogue response in speech form. In yet other examples, the generated response is data content relevant to satisfying a user request in the speech input.

In examples where task flow processing module 736 receives multiple structured queries from natural language processing module 732, task flow processing module 736 initially processes the first structured query of the received structured queries to attempt to complete the first structured query and/or execute one or more tasks or actions represented by the first structured query. In some examples, the first structured query corresponds to the highest ranked actionable intent. In other examples, the first structured query is selected from the received structured queries based on a combination of the corresponding speech recognition confidence scores and the corresponding intent confidence scores. In some examples, if task flow processing module 736 encounters an error during processing of the first structured query (e.g., due to an inability to determine a necessary parameter), the task flow processing module 736 can proceed to select and process a second structured query of the received structured queries that corresponds to a lower ranked actionable intent. The second structured query is selected, for example, based on the speech recognition confidence score of the corresponding candidate text representation, the intent confidence score of the corresponding candidate actionable intent, a missing necessary parameter in the first structured query, or any combination thereof.

Speech synthesis processing module 740 is configured to synthesize speech outputs for presentation to the user. Speech synthesis processing module 740 synthesizes speech outputs based on text provided by the digital assistant. For example, the generated dialogue response is in the form of a text string. Speech synthesis processing module 740 converts the text string to an audible speech output. Speech synthesis processing module 740 uses any appropriate speech synthesis technique in order to generate speech outputs from text, including, but not limited, to concatenative synthesis, unit selection synthesis, diphone synthesis, domain-specific synthesis, formant synthesis, articulatory synthesis, hidden Markov model (HMM) based synthesis, and sinewave synthesis. In some examples, speech synthesis processing module 740 is configured to synthesize individual words based on phonemic strings corresponding to the words. For example, a phonemic string is associated with a word in the generated dialogue response. The phonemic string is stored in metadata associated with the word. Speech synthesis processing module 740 is configured to directly process the phonemic string in the metadata to synthesize the word in speech form.

In some examples, instead of (or in addition to) using speech synthesis processing module 740, speech synthesis is performed on a remote device (e.g., the server system 108), and the synthesized speech is sent to the user device for output to the user. For example, this can occur in some implementations where outputs for a digital assistant are generated at a server system. And because server systems generally have more processing power or resources than a user device, it is possible to obtain higher quality speech outputs than would be practical with client-side synthesis.

Additional details on digital assistants can be found in the U.S. Utility application Ser. No. 12/987,982, entitled “Intelligent Automated Assistant,” filed Jan. 10, 2011, and U.S. Utility application Ser. No. 13/251,088, entitled “Generating and Processing Task Items That Represent Tasks to Perform,” filed Sep. 30, 2011, the entire disclosures of which are incorporated herein by reference.

4. Exemplary Functions and Architectures of a Speech-to-Text (STT) Processing Module Performing Speech-to-Text Conversion in a Multi-Speaker Environment.

FIG. 8 illustrates a block diagram of a STT processing module 800 for performing a speech-to-text (STT) conversion in a multi-speaker environment using a single learning network 830, according to various examples. A learning network is a computer-implemented network or model capable of performing a task without using explicit instructions. A learning network is capable of being trained to make predictions or decisions without being explicitly programmed to perform a task. A learning network can include, for example, neural network models, deep learning networks, statistic models, and other algorithms capable of being trained. In some examples, STT processing module 800 is implemented by a digital assistant system (e.g., system 700) operating on a user device according to various examples. In some examples, the user device, a server (e.g., server 108), or a combination thereof, can implement the STT processing module 800 of the digital assistant. The user device can be implemented using, for example, device 104, 200, 400, and 600 as illustrated in FIGS. 1, 2A-2B, 4, and 6A-6B. In some examples, STT processing module 800 can be implemented using STT processing module 730 of digital assistant system 700. STT processing module 800 can include one or more modules, systems, models, applications, vocabularies, and user data similar to those of STT processing module 730. For example, STT processing module 800 can include the following sub-modules, or a subset or superset thereof: a feature extractor, an ASR system, and a decoder. In some embodiments, these modules can also be implemented similar to that of the corresponding modules as illustrated in FIG. 7B, and therefore are not shown and not repeatedly described.

With reference to FIG. 8, STT processing module 800 of a virtual assistant receives mixed speech data 801. Mixed speech data 801 represent utterances 801A of a target speaker and utterances 801B of one or more interfering audio sources. A target speaker is a user who is attempting to speak (e.g., provide audio input) to a virtual assistant. In some instances, while the target speaker is speaking to the virtual assistant, one or more other interfering audio sources may be detected, e.g., other speakers may be speaking to one another in a close proximity (e.g., in the same room or house). As another example, while the target speaker is speaking to the virtual assistant, an electronic device may be outputting audio (e.g., speech from a TV) that is detected concurrently with utterances from the target speaker. Thus, under certain circumstances, while the target speaker is providing audio inputs to the virtual assistant, there may be one or more interfering audio sources (from other speakers or electronic devices) producing audio outputs. In such instances, it is desirable for the virtual assistant to distinguish the speech inputs of the target from speech inputs of interfering audio sources in such a multi-speaker environment. In this application, a speech input is sometimes referred to as one or more utterances. For example, a speech input can include a single utterance or multiple utterances.

In some embodiments, as illustrated in FIG. 8, utterances 801A of the target speaker and utterances 801B of the interfering audio sources can at least partially overlap in time (e.g., multiple speakers are speaking simultaneously). As a result, STT processing module 800 of the virtual assistant receives mixed speech data 801 that represent the at least partially overlapped utterances. Mixed speech data 801 can be defined in formula (1) below. s _(mix)(t)=s _(T)(t)+Σ_(n=1) ^(N) s _(n)(t)  (1) In formula (1), s_(mix)(t) denotes mixed speech data 801 at any given time t; s_(T)(t) denotes the speech signal (e.g., acoustic signals or audio frames) representing utterances 801A of the target speaker at any given time t; and s_(n)(t) denotes the speech signal (e.g., acoustic signals or audio frames) representing utterances 801B of the nth interfering audio source. In formula (1), n=1, 2, . . . , N and N denotes the total number of interfering audio sources.

In some embodiments, mixed speech data 801 include acoustic representations of a plurality of audio frames corresponding to utterances 801A of the target speaker and utterances 801B of the one or more interfering audio sources. Each audio frame can be associated with a predetermined period of time (e.g., 10 millisecond or 10 ms). Mixed speech data 801 can thus be separated into audio frames for subsequent processing. For example, with reference to FIG. 8, to extract the feature vectors 822, acoustic features can be extracted for every audio frame (e.g., every 10 ms). In some embodiments, feature vectors 822 can include acoustic features extracted from multiple audio frames. For example, at any given time t, feature vectors can be extracted from a current audio frames at time t, one or more preceding audio frames (e.g., audio frames of preceding time steps t−1, t−2, etc.), and one or more following audio frames (e.g., audio frames of following time steps t+1, t+2, etc.). The features vectors so extracted can be concatenated together and provided to learning network 830 as an input. Feature extraction is described in more detail below.

As illustrated in FIG. 8, based on the received mixed speech data, STT processing module 800 can extract acoustic features and generate feature vectors 822. A feature extractor 820 can be used to perform feature extraction. Feature extractor 820 can be, for example, a front-end speech pre-processor. A front-end speech pre-processor can extract representative features from received speech data. For example, a front-end speech pre-processor can perform a Fourier transform on the received speech input to extract spectral features that characterize the speech input as a sequence of representative multi-dimensional vectors. A feature of the speech input can represent one or more spectrum characteristics associated with the spectrum of the speech input. For example, a feature may include a mel-frequency cepstrum coefficient (MFCC). A plurality of MFCCs can represent a mel-frequency cepstrum (MFC). An MFC can be a representation of a short-term power spectrum of the speech input. In some embodiments, feature extractor 820 can include a Log Mel filterbank (LMFB), which applies a triangular filter bank with Mel-warping to the received speech input and obtains a single coefficient output for each filter of the filter bank. A log operation can be applied on each coefficient to reduce the dynamic range. In some embodiments, based on the processing of the speech input, feature extractor 820 can extract a 40-dimensional (40-D) LMFB feature vector per audio frame of mixed speech data 801. These feature vectors can form feature vectors 822, which are provided as inputs to learning network 830 for further processing.

As illustrated in FIG. 8, in some embodiments, in addition to receiving feature vectors 822, STT processing module 800 also receives a target speaker representation 824. Target speaker representation 824 represents speech characteristics (e.g., tone, pitch, accent, etc.) of the target speaker. Target speaker representation 824 can be a target speaker vector that is used to improve the accuracy (reduce the word error rate) of speech-to-text conversion in a multi-speaker environment. For example, a target speaker vector can be a 128-dimensional (128-D) vector uniquely identifying the target speaker. A target speaker vector can be obtained from a pre-trained long short-term memory (LSTM) based speaker verification system (or any recurrent neural network (RNN) based system). In some embodiments, a pre-trained LSTM-based speaker verification system can be an application (e.g., one of applications 724) or a sub-system that is part of a digital assistant module (e.g., module 726).

A target speaker vector can be pre-generated or generated on-the-fly. To pre-generate a target speaker vector (e.g., before mixed speech data is received in a multi-speaker environment), a pre-trained LSTM-based speaker verification system receives enrollment utterances from the target speaker and generates the target speaker vector based on the enrollment utterances received from the target speaker. For example, the enrollment utterances can be provided by the target speaker (e.g., the user of his or her mobile/client device) to a virtual assistant during an initial device setup process. The virtual assistant can be operating on the target speaker's user device or operating on a combination of a user device and a server. The enrollment utterances typically include only utterances from the target speaker, and no or negligible audios (e.g., background noises) from other interfering audio sources. As a result, the pre-trained LSTM-based speaker verification system receives clean enrollment utterances from the target speaker. The clean enrollment utterances are thus known to be provided by the target speaker and can be used as inputs to the pre-trained LSTM-based speaker verification system for extracting features of speeches from the target speaker. The feature extraction process can be performed similarly to those described above using a feature extractor (e.g., a feature extractor 820).

In some embodiments, a pre-trained LSTM-based speaker verification system may not receive enrollment utterances before speech recognition needs to be performed on the mixed speech data. For example, the target speaker may have elected to skip providing enrollment utterances during the device setup process. Or a device (e.g., a home assistant device or a smart speaker) may be shared by multiple users. In such instances, the device setup process may not require enrollment utterances because multiple users are expected to use the device. As a result, the target speaker vector may not be pre-generated. In some embodiments, the pre-trained LSTM-based speaker verification system can generate a target speaker vector on-the-fly. For example, the pre-trained LSTM-based speaker verification system can generate the target speaker vector based on a trigger phrase uttered by the target speaker (e.g., “Hey Assistant”). The trigger phrase is a phrase to invoke a virtual assistant session. In some embodiments, the trigger phrase is part of the utterances represented by mixed speech data 801 that the virtual assistant receives. For example, the target speaker may utter “Hey Assistant, how is the weather today?” Typically, a trigger phrase is only uttered by the target speaker (e.g., the user who is speaking to the virtual assistant) and not by any interfering audio source (e.g., by another user speaking in the background, or by an actor in a TV show). Because the trigger phrase is often uttered only by the target speaker, the pre-trained LSTM-based speaker verification system can use the trigger phrase to determine a target speaker vector. For example, the trigger phrase can be used as inputs to the pre-trained LSTM-based speaker verification system for extracting features of speeches from the target speaker. Feature extraction can be performed similarly to those described above using a feature extractor (e.g., a feature extractor 820).

In some embodiments, a target speaker vector can be denoted by sv_(T). Because the target speaker vector represents the speech characteristics of the target speaker, the speaker-aware acoustic models described below in detail can be used to perform speech recognition of the target speaker speech inputs by conditioning the senone probability distributions to the target speaker vector. Formula (2) below shows such a speaker-aware acoustic model denoted bye

. σ_(T)=

(s _(mix) ,sv _(T))  (2) In formula (2), sv_(T) denotes the target speaker vector; s_(mix) denotes the mixed speech data of formula (1) shown above;

denotes the speaker-aware acoustic model that receives the target speaker vector sv_(T) and mixed speech data s_(mix) as inputs; and σ_(T) denotes the senone posterior probability distribution. The speaker-aware acoustic model denoted by

can be, for example, an augmentation-based acoustic model or an attention-based acoustic model used in learning network 830. The different types of speaker-aware acoustic models are described in detail below.

In some embodiments, the speaker-aware acoustic models are used to generate posterior probability distributions of phonetic elements directly from mixed speech data 801. A phonetic element can be a phoneme, phone, diphone, triphone, or a senone. A secone can be a part or parts of a phoneme or a phone. As described above, when a speech input is received, STT processing module 730 is used to determine the phonemes corresponding to the speech input (e.g., using an acoustic model), and then attempt to determine words that match the phonemes (e.g., using a language model). A phoneme can include one or more phones. In some embodiments, phones are clustered based on context to form diphones, triphones, and quinpones. For example, a phone “u” with left phone “b” and right phone “d” in the word “bad” sounds a bit different than the same phone “u” with left phone “b” and right phone “n” in word “ban”. Thus, instead one representation of a phoneme, a phoneme can be represented in three parts based on context: a beginning part of the phoneme, a middle part of the phoneme, and an ending part of the phoneme. A senone can be tied states within context-dependent phones. A senone can encode phone sequence information, and thus can be a basic phonetic unit for generating pronunciation of a word. For example, the English language has about 44 distinct phones, which can form several thousands of senones. In forming the senones, for example, triphones with the same central phone and similar sounds can be clustered together to the same senones.

With reference to FIG. 8, learning network 830 receives feature vectors 822 and target speaker representation 824 for generating, for example, senone posterior probability distributions 832. It is appreciated that learning network 830 can also be used to generate posterior probability distributions of other types of phonetic elements, such as phonemes. In some embodiments, learning network 830 is a single machine learning network for performing speech-to-text conversion in a multi-speaker environment. A single learning network can have an input layer (e.g., a layer that provides input feature vectors to the subsequent layers), a plurality of hidden layers, and an output layer. In contrast, conventional techniques for performing speech-to-text conversion in a multi-speaker environment often require two separate machine learning networks. That is, one neural network is required for separating the utterances of the target speaker from the utterance of interfering audio sources, and generating an intermediate speech data that represent only the utterances of the target speaker. And another separate neural network is required for converting the speech data that represent only the utterances of the target speaker to text. The techniques described in this application do not require the generation of the intermediate speech data that represent only the utterances of the target speaker. Therefore, the learning network described in this application can be a single machine learning network that enables a direct generation of texts corresponding to the utterances of the target speaker using the mixed speech data.

FIG. 9A illustrates a block diagram of a learning network 830A. Learning network 830A is one embodiment of learning network 830 shown in FIG. 8. In some embodiments, learning network 830A can include a first portion 840A and a second portion 860A. First portion 840A can include, for example, one or more convolutional layers 902 and optionally one or more pooling layers (not shown). In some embodiments, convolutional layer 902 can be a hidden layer. Second portion 860A can include, for example, one or more hidden layers 906A-N. As one example, learning network 830A can be a convolutional neural network (CNN) including one or more convolutional layers and one or more pooling layers (e.g., a max-pooling layer) in first portion 840A, and including five fully-connected hidden layers in second portion 860A. As another example, learning network 830A can be a bidirectional convolution LSTM deep neural network (BCLDNN) having one or more convolutional layers, one or more pooling layers (e.g., a max-pooling layer), and six bi-directional long short-term memory (BLSTM) hidden layers.

As shown in FIG. 9A, one or more convolutional layers 902 receive feature vectors 822 and perform a convolutional operation to feature vectors 822. In some embodiments, the one or more convolutional layers 902 include one or more independent filters. Each filter can be independently convolved with feature vectors 822. In some embodiments, the convolutional layers 902 increase the dimensions or the size of the feature vectors 822. In some embodiments, a plurality of convolutional layers 902 are connected in sequence.

In some embodiments, first portion 840A of learning network 830A can further include one or more pooling layers (not shown). The one or more pooling layers receive the output of the one or more convolutional layers 902 and generate an intermediate representation of mixed speech data 801. The one or more pooling layers can perform pooling operations, which combine the outputs of neuron clusters at one layer into a single neuron in the next layer. A pooling layer can perform average pooling, max pooling, or any other desired type of pooling operations. An average pooling operation performs, for example, down-sampling by dividing the input vectors into pooling regions and computing the average values of each region. Average pooling in this way increases the effective modeling span by distilling large sets of data into a finite vector. A max pooling operation performs, for example, down-sampling by using the maximum value from each of a cluster of neurons at the prior layer.

As shown in FIG. 9A, in some embodiments, feature vectors 822 are processed by the one or more convolutional layer 902 and optionally one or more pooling layers (not shown) of first portion 840A of learning network 830A. The processing result of first portion 840 can be, for example, intermediate vectors 904. Because feature vectors 822 are generated from mixed speech data 801, intermediate vectors 904 are thus an intermediate representation of mixed speech data 801. First portion 840A of learning network 830A can provide intermediate vectors 904 as input vectors to second portion 860 of learning network 830A. As described above, in some embodiments, a feature vector (e.g., a 40-dimensional LMFB vector) can be extracted from one or more audio frames corresponding to a pre-determined time period (e.g., 10 ms). Thus, one or more of feature vectors 822 can represent a plurality of audio frames (e.g., adjacent audio frames) associated with a context window. A context window can include, for example, twenty-one audio frames centered around the middle audio frame (e.g., a current audio frame, ten preceding audio frames, and ten following audio frames). Consequently, intermediate vectors 904 can correspond to a feature vector that represents a plurality of audio frames associated with a context window.

FIG. 9A illustrates an augmentation-based speaker-aware acoustic model. As illustrated in FIG. 9A, second portion 860A of learning network 830A can include a plurality of hidden layers 906A-N (collectively as 906). A hidden layer is a layer between an input layer of a neural network and an output layer of the neural network. The hidden layer can include a layer of neurons. Each of the hidden layers can perform certain functions based on its input vectors and generate output vectors, which are in turn input vectors to the next layer. Hidden layers 906A-N can be, for example, fully-connected hidden layers in a convolutional neural network (CNN), with each layer having 1024 nodes. In some embodiments, an intermediate vector 904 can be augmented to account for the target speaker representation 824. For example, as shown in FIG. 9A, an intermediate vector 904 can be concatenated with target speaker representation 824 (e.g., a target speaker vector as described above) to generate the input vector to hidden layer 906A. Hidden layer 906A is the first hidden layer of second portion 860A of learning network 830A. Based on the input vector to hidden layer 906A, an output vector of hidden layer 906A can be determined.

The output vector of hidden layer 906A can then be concatenated with target speaker representation 824 to form the input vector to hidden layer 906B, which is the next hidden layer. And the output vector of hidden layer 906B can thus be determined. As shown in FIG. 9A, similarly, the output vector of each preceding hidden layer can be concatenated with the target speaker representation 824 to form the input vector of the following hidden layer. And the output vector of the following hidden layer can thus be determined. If x denotes the output vector of a preceding hidden layer (or the intermediate vector 904), sv_(T) denotes the target speaker representation 824 (e.g., a target speaker vector), and y denotes the output vector of the current hidden layer, formula (3) below describes a relation between the input vector x and the output vector y. y=

([x,sv _(T)])  (3) In the above formula (3),

denotes the function performed by the current hidden layer. In some embodiments, target speaker representation 824 is concatenated to each output vector of the preceding hidden layer (or the intermediate vector 904). Using the target speaker representation 824 in the input vector of each hidden layer can improve the accuracy of speech-to-text conversion of the utterances from the target speaker in a multi-speaker environment. For example, the word error rate can be greatly reduced in this manner.

In some embodiments, as illustrated in FIG. 9A, the output vector of last hidden layer 906N can be provided as input vector to an output layer 908. Output layer 908 can perform a softmax activation function to generate posterior probability distributions of phonetic elements (e.g., senone posterior probability distributions 832). A softmax activation function can take an input vector and normalize it into probability distributions. The output of output layer 908 thus include senone probability distributions conditioned upon the target speaker representation 824, because target speaker representation 824 is used as part of the input vector to the hidden layers 906A-N. The conditioned probability distributions are referred to as posterior probability distributions.

FIG. 9B illustrates a block diagram of a learning network 830B, which is another embodiment of learning network 830 shown in FIG. 8. In some embodiments, similar to learning network 830A, learning network 830B can include a first portion 840B and a second portion 860B. First portion 840B can include, for example, one or more convolutional layers 902 and optionally one or more pooling layers (not shown). Second portion 860 can include, for example, one or more hidden layers 916A-N. As one example, learning network 830B can be a convolutional neural network (CNN) having one or more convolutional layers, one or more pooling layers (e.g., a max-pooling layer), and five attention-based hidden layers. As another example, learning network 830B can be a BCLDNN network having one or more convolution layers, one or more pooling layers (e.g., a max-pooling layer), and six bi-directional long-short term memory (BLSTM) attention-based hidden layers.

First portion 840B of learning network 830B can be the substantially the same as or similar to first portion 840A described above for learning network 830A, and thus is not repeatedly described. In some embodiments, similar to described above with respect to FIG. 9A, feature vectors 822 can be processed by first portion 840B of learning network 830B. The processing result of the first portion 840B can be, for example, intermediate vectors 914. Because feature vectors 822 are generated from mixed speech data 801, intermediate vectors 914 are thus an intermediate representation of mixed speech data 801.

With reference to FIG. 9B, similar to second portion 860A of learning network 830A, second portion 860B of learning network 830B can include a plurality of hidden layers 916A-N (collectively as 916) and an output layer 918. Hidden layers 916 shown in FIG. 9B can be attention-based and have a structure that is different from hidden layers 906 shown in FIG. 9A. An exemplary hidden layer 916 is illustrated in FIG. 9C.

In some embodiments, as shown in FIG. 9C, a hidden layer 916 can receive an input 912. Input 912 can be, for example, an intermediate representation of mixed speech data 801, such as intermediate vectors 914 or the output vector of a preceding hidden layer shown in FIG. 9B (denoted by x). Hidden layer 916 can receive another input that is the target speaker representation 824, denoted by sv_(T). Unlike a hidden layer 906 shown in FIG. 9A, hidden layer 916 does not require that target speaker representation 824 (e.g., a target speaker vector) be concatenated with input 912. Moreover, as described below, in some embodiments, a hidden layer 916 replaces a fully-connected layer (e.g., hidden layer 906) with a speaker-aware hidden layer.

In some embodiments, the structure of hidden layer 916 represents a part of an attention-based acoustic model. An attention-based acoustic model can map a query and a set of key-value pairs to an output, where the query, keys, values, and output are all vectors. In some embodiments, the output of an attention-based acoustic model is computed as a weighted sum of the values, where the weight assigned to each value is computed by a compatibility function of the query with the corresponding key. For example, as shown in FIG. 9C, input 912 (e.g., a vector that is the intermediate representation of the mixed speech data or an output vector from the preceding hidden layer) can be projected to a plurality of pairs of embedding vectors that include acoustic embeddings 934A-M and keys 936A-M. An example of the projection of input 912 to acoustic embeddings 934A-M and keys 936A-M are illustrated in formula (4) and shown in FIG. 9C. [v ₁ ,v ₂ , . . . ,v _(M) ,k ₁ ,k ₂ , . . . ,k _(M)]=

(x)  (4)

In formula (4), input 921 is denoted by x, and the projection or mapping of input 912 is denoted by

(x). In formula (4), v_(m) denotes acoustic embeddings (shown as 934A-M in FIG. 9C); k_(m) denotes keys (shown as 936A-M in FIG. 9C) for an attention mechanism; and M denotes the total number of acoustic embeddings. In some embodiments, the attention mechanism depends on an external target speaker representation and thus may not be a self-attention mechanism. In some embodiments, input 912 (e.g., the intermediate vector representing the mixed speech data), can be projected to vectors v and k, which may have different dimensions from input 912. The keys k_(m) can be generated by a non-linear projection function

(x). Acoustic embeddings v can be representations of the acoustic features extracted from the mixed speech data. As attention mechanism is an attention mechanism relating different positions of a single sequence in order to compute a representation of the sequence.

The attention mechanism enables learning network 830B to attend to the utterances of the target speaker. For example, the target speaker representation 824 (denoted by sv_(T)) is used as the attention queries in the attention mechanism. A non-linear function

is used to determine scalar coefficients (denoted by α_(m) based on the target speaker representation sv_(T) and keys k_(m). Formula (5) represents such a determination. α_(m)=

(k _(m) ,sv _(T))  (5)

Formula (5) is also illustrated in FIG. 9C. For example, for each acoustic embedding 934A-M denoted by v_(m)), the non-linear function

can be applied to the corresponding key 936A-M (denoted by k_(m)) using the target speaker representation 824 as queries. The results of applying the non-linear function

can be scalar coefficients 939A-M, denoted by α_(m). As shown in FIG. 9C, in some embodiment, one scalar coefficient 939 is generated corresponding to one acoustic embedding 934.

In some embodiments, as shown in FIG. 9C, an output 962 (denoted by y) of hidden layer 916 can be determined based on the acoustic embeddings 934A-M and the scalar coefficients 939A-M. For example, a weighted sum 942 can be computed using each of the scalar coefficients 939A-M and the corresponding acoustic embeddings 934A-M. A layer activation function 952 can be applied to the weighted sum 942 to obtain output 962 of hidden layer 916. Formula (6) represents such a determination of output 962. y=φ(Σ_(m=1) ^(M)(α_(m) ×v _(m)))  (6)

In formula (6), y denotes the output of a hidden layer (e.g., layer 916); φ denotes an activation function (e.g., a non-linear activation function such as an exponential linear unit (ELU) function); M denotes the number of acoustic embeddings; α_(m) denotes the mth scalar coefficient; and v_(m) denotes the mth acoustic embeddings. In formula (6), the scalar coefficients thus are used as weights for the different acoustic embeddings. As described above, the scalar coefficients 939A-M are generated by taking into account the target speaker representation 824 denoted by sv_(T). As a result, the attention mechanism implemented by one or more hidden layers 916 thus enables learning network 830B to attend to the target speaker characteristics. For example, acoustic embeddings that are more related to the target speaker are weighted more in the attention-based speaker aware acoustic model illustrated by FIG. 9C.

As discussed above, hidden layer 916 shown in FIG. 9C can be used to implement any of hidden layers 916A-N shown in FIG. 9B. With reference in FIG. 9B, an output vector of a preceding vector hidden layer can be an input vector of a following hidden layer. For example, the output vector of hidden layer 916A can be an input vector of hidden layer 916B. In some embodiments, hidden layer 916B can also receive the target speaker representation 824. Thus, the output vector of hidden layer 916B can be determined similarly by using the target speaker representation 824 as queries in an attention mechanism implemented by the structure of hidden layer 916B. The output vector of hidden layer 916B can in turn be used as input vector of hidden layer 916C, and so forth. As a result, in some embodiments, each hidden layer 916 in section portion 860B receives target speaker representation 824 as queries.

The attention-based hidden layers 916 described above depend on both the target speaker representation and acoustic embeddings generated from one or more audio frames of the mixed speech data. Thus, the attention-based hidden layer 916 enables learning network 830B to use a single neural network to perform speech-to-text conversion in a multi-speaker environment. In contrast, convention technologies may require two separate neural networks, one for separating the utterances of the target speaker from the utterances of interfering audio sources, and one for converting the separated utterances of the target speaker to text. For example, traditional technologies may require separation of the mixed speech data to multiple audio streams, each representing utterances from a particular speaker. Then, based on the target speaker speech characteristics, one audio stream is selected for performing speech recognition and conversion to text. The traditional techniques are thus inefficient and error prone. For example, because the traditional techniques require two separate neural networks for performing speech separation and speech recognition, two separate trainings of the networks are thus required with two separate sets of training data. This is often cumbersome and inefficient. For instance, separated clean speech data from multiple audio sources may not be readily available for the purpose of training the neural network for speech separation. Also, interfering audio sources may often vary and thus one set of training data may not be sufficient. The techniques described in this application eliminate the requirement for separating the speeches, and combine the traditional speech separation and the speech recognition steps into one step by using one improved speaker-aware acoustic model. As described in more detail below, the techniques described in this application greatly improve the efficiency in training the model, because the training of the model does not rely on the availability of an intermediate training target (e.g., separated clean speeches) and also does not require separate trainings of two interconnected learning networks (e.g., one for speech separation and one for speech recognition). Training of two interconnected learning networks can be sometimes cumbersome and difficult because optimization of one network does not necessarily mean optimization of the other network. The techniques described in this application require training of only one learning network that includes the improved speaker-aware acoustic model. Thus, the single learning network can be trained and optimized to obtain an improved trained model. Such a trained model enhances the accuracy and efficiency of speech recognition compared to traditional techniques.

Moreover, in traditional techniques, while an attention mechanism may be used for the separation of the utterances of the target speaker from the utterances of interfering audio sources, such an attention mechanism may only depend on the target speaker speech characteristics and not on the acoustic embeddings of the mixed speech data. Such an attention mechanism thus does not account for any impact of the target speaker speech characteristics by different interfering audio sources. As discussed above, interfering audio sources may often vary. Thus, by not taking into account for the impact of the variation of the interfering audio sources to the target speaker speech characteristics, conventional techniques have less accuracy.

Further, some existing techniques using attention mechanisms often attend to feature vectors extracted from different input audio frames. As a result, the performance of these existing techniques may be degraded because it is falsely assumed that each audio frame is dominated by one speaker. But in a multi-speaker environment, it is likely that some audio frames may contain overlapping speech inputs from multiple speakers. The attention mechanism described in this application can attend to speeches from different speakers extracted from a same audio frame. As a result, the techniques in this application do not assume that each audio frame is dominated by one speaker. Rather, using the attention mechanism described in this application, the performance of speech recognition in a multi-speaker environment do not degrade, but rather improves, even if there are overlapping speech inputs from multiple speakers in some audio frames.

With reference back to FIG. 9B, second portion 860B of learning network 830B can include an output layer 918. Output layer 918 can be substantially the same or similar to output layer 908 shown in FIG. 9A and described above. Thus, output layer 918 is not repeatedly described. Output layer 918 can receive the output vector of the last hidden layer 916N and generate senone posterior probability distributions 832.

With reference back to FIG. 8, in some embodiments, STT processing module 800 further includes a decoder 880. Decoder 880 receives senone posterior probability distributions 832 generated by learning network 830 as inputs. For example, a sequence of senone posterior probability distributions 832 can be generated by learning network 830 based on multiple audio frames of mixed speech data 801. A decoder 880 can transform the sequence of senone posterior probability distributions to text (e.g., a sequence of words) corresponding to the utterances 801A of the target speaker In some embodiments, decoder 880 can search through all the possible output sequences based on their probabilities, using the senone posterior probability distributions 832. For example, decoder 880 can a beam-search decoder that performs beam-search decoding. During the beam-search decoding, decoder 880 can expand all possible next steps and keep a predetermined number of most likely steps. The number of the most likely steps can be a user-specified parameter, based on which the number of beams or parallel searches through the sequence of probabilities is determined. Based on the probability distributions, decoder 880 can generate text 882 corresponding to utterances of the target speaker. It is appreciated that decoder 880 can also be other types of decoders such as a greedy-search decoder.

As shown in FIG. 8 and discussed above, unlike conventional techniques for performing speech-to-text conversion in a multi-speaker environment, the speaker-aware acoustic models described in this application do not require separate learning networks for speech separation and for speech recognition. Using the single learning network 830, mixed speech data 801 can be processed to generate text 882 corresponding to the utterances of the target speaker. The techniques describes in this application thus improve the efficiency of the speech-to-text process. Further, because learning network 830 uses improved speaker-aware acoustic models (e.g., augmentation-based model as shown in FIG. 9A or attention-based model as shown in FIG. 9B) to account for target speaker representation 824, the accuracy of the speech-to-text conversion is also improved. For example, word error rates or insertion error rates of the STT conversion can be significantly reduced by using the techniques described in this application (e.g., reduced by about 20-80%), as compared to using conventional techniques.

In some embodiments, after text 882 is generated by STT processing module 800, the virtual assistant can provide a response to the target speaker. For example, the virtual assistant can determine a user intent based on text 882 corresponding to the utterances of the target speaker; and perform one or more tasks based on the determined user intent. The determination of user intent and performing of tasks are described in detail above (e.g., FIG. 7B shows processing text through natural language processing module 732, generating structure queries, etc.).

In some embodiments, the speaker-aware acoustic models of learning network 830 can be trained before the learning network is used to perform speech-to-text conversion. FIG. 10 illustrates a block diagram of training learning network 830 of STT processing module 800. The training of learning network 830 can be performed on one or more server systems (e.g., server system 108), one or more client devices (e.g., user device 104), or a combination thereof. With reference to FIG. 10, in some embodiments, in training of learning network 830, STT processing module 800 obtains a first set of training data 1006. First set of training data 1006 can include mixed utterances from a target speaker and utterances from one or more interfering audio sources. For example, for mixing the utterances to obtain first set of training data 1006, a second set of training data 1002 can be obtained first. The second set of training data 1006 include, for example, recordings of utterances from one or more speakers. The one or more speakers can include one or more target speakers or any other speakers for the training purpose. In some embodiments, each recording in the second set of training data 1006 can include utterances from only a single speaker. The utterances from the single speaker can include utterances for a predetermined period of time (e.g., 1000 hours) obtained for training the learning network 830. In some embodiments, the utterances can include statements, commands, queries, requests for the virtual assistant, and any other type of speeches. In addition, the second set of training data 1006 can also include text corresponding to the utterances from the single speaker. The text can be manually transcribed to ensure that they correctly correspond to utterances.

As illustrated in FIG. 10, in some embodiments, to generate first set of training data 1006, utterances 1004 of one or more interfering audio sources can also be obtained. For example, utterances 1004 can include speeches from one or more speakers other than the speaker associated with the second set of training data 1002, speeches from TV, radio, or any other audio sources. In some embodiments, utterances included in second set of training data 1002 (e.g., utterances from only one speaker) can be acoustically mixed with the utterances 1004 of interfering audio sources. The acoustic mixing can be performed at different target-to-interferer (TIR) ratios (e.g., 12 dB, 6 dB, or 0 dB). Further, in some embodiments, in performing the acoustic mixing, a randomly selected time within the utterances included in second set of training data 1002 can be used as the starting point for mixing with the utterances 1004 of interfering audio sources. In some embodiments, after the acoustic mixing, first set of training data 1006 can include audio frames or time periods associated with utterances of only one speaker, mixed utterances of multiple speakers, and silence (e.g., no utterance for some audio frames). In some embodiments, similar to the mixed speech data 801 described above, first set of training data 1006 include acoustic representation of a plurality of audio frames. Each audio frame can have a predetermined period of time (e.g., 10 ms).

In some embodiments, as shown in FIG. 10, for training learning network 830 of STT processing module 800, a target speaker representation 1024 can be obtained. The target speaker used for training can be the same speaker whose utterances are included in second set of training data 1002. Target speaker representation 1024 can represent speech characteristics of the target speaker. In some embodiments, one or more utterances (e.g., 10 utterances) can be selected from the utterances represented by second set of training data 1002. These selected utterances can be used as enrollment utterances for generating target speaker representation 1024. In some embodiments, the selected utterances include trigger phrases (e.g., “Hey, Assistant”). Using the selected utterances, target speaker representation 1024 can be generated in a similar manner as described above for target speaker representation 824 in FIG. 8. For example, in a similar manner as described above, a 128-dimensional feature vector can be generated to represent the speech characteristics of the target speaker.

Using first set of training data 1006 and second set of training data 1002, the speaker-aware acoustic model included in learning network 830 can be trained. In some embodiments, the training is performed in multiple or many rounds of iterations. In each of the iteration, a number of steps are performed similarly to those described above. For example, as shown in FIG. 10, in each iteration of the training process, an intermediate representation 842 of a portion of (e.g., a number of audio frames in a context window) first set of training data 1006 can be generated. Similar to those described above, to generate the intermediate representation 842, feature vectors 822 (e.g., a 40-dimensional LMFB) can be extracted from a plurality of audio frames corresponding the utterances represented by the portion of first set of training data 1006. Feature vectors 822 can be used as inputs to first portion 840 of learning network 830. Based on the extracted feature vectors, first portion 840 of learning network 830 can generate the intermediate representation 842 representing a portion of the first set of training data 1006. First portion 840 can include one or more convolution layers and one or more pooling layers. Thus, similar to those described above, feature vectors 822 can be processed through these layers. And the intermediate representation 842 (e.g., vectors with reduced dimensions from the feature vectors 822) can be obtained based on the processing results.

With reference to FIG. 10, in each iteration of training process, probability distributions of phonetic elements can be determined based on the intermediate representation 842 using second portion 860 of learning network 830. The determination is performed similar to those described above. For example, second portion 860 of learning network 830 can include different types of hidden layers as described in FIGS. 9A-9C (e.g., augmentation-based hidden layer or attention-based hidden layer). As described above, the different types of hidden layers can be used to form different types of acoustic models, for example, an augmentation-based acoustic model (shown in FIG. 9A) or an attention-based acoustic model (shown in FIGS. 9B-9C). In some embodiments, second portion 860 generates senone posterior probability distributions 832, which can be provided to decoder 880.

As shown in FIG. 10, in a similar manner as described above, decoder 880 can generate text 882 corresponding to the utterances of the target speaker based on the senone posterior probability distributions 832. Based on the generated texts, the virtual assistant can adjust one or more parameters of the acoustic models included in learning network 830 (e.g., parameters of first portion 840 and/or second portion 860). For example, as shown in FIG. 10, a difference evaluator 1020 can be included in the virtual assistant to evaluate the difference between text 1082 and text 1012. Text 1082 corresponds to the utterances of the target speaker and is generated based on first set of training data 1006. Text 1012 also corresponds to the same utterances of the target speaker, and is included in the second set of training data 1002 (e.g., it is a manually transcribed text from the utterances). Difference evaluator 1020 can thus compare text 1082 and text 1012 to determine, for each iteration, whether text 1082 differs more from text 1012 or differs less from text 1012. Based on the determination, difference evaluator 1020 can cause one or more parameters of learning network 830 to be adjusted accordingly. For example, based on the determination, weights of the neurons or nodes of the multi-layer perceptron (MLP) included in the acoustic model of second portion 860 of learning network 830 can be adjusted. It is appreciated that the training process can be performed with as many iterations as desired (e.g., until convergence). The trained speaker-aware acoustic model can thus be provided for speech recognition and conversion the speech of the target speaker to text in a multi-speaker environment as described above.

The training process described above is performed with respect to a single learning network 830. The target speaker utterances (and corresponding text) included in second set of training data 1002 are used as training target. The using of a single learning network eliminates the need for an intermediate target vector for training a speech separation network used in traditional techniques. As described above, traditional techniques require two separate neural networks—a first neural network for speech separation and a second neural network for speech recognition. As a result, the two separate neural networks need to be separately trained. Training of the neural network for speech separation thus require generating intermediate target vectors representing the audio signals from the target speaker, for the purpose of adjusting the parameters of the first neural network. This can be cumbersome and inefficient. Further, training the two neural networks separately may not provide optimum training results for the overall system. For example, the first neural network may be trained to optimize based on criteria that are irrelevant to the second neural network, and vice versa. Thus, the separately trained two neural networks may not result in an optimum trained overall system. The techniques described in this application eliminates the requirements for performing separate trainings of two neural networks because a single neural network having speaker-aware acoustic model is used. This greatly improves training efficiencies and reduces the requirements for preparing training data.

FIGS. 11A-11C illustrate an exemplary process 1100 for operating a digital assistant to perform speech-to-text conversion in a multi-speaker environment, according to various examples. Process 1100 is performed, for example, using one or more electronic devices implementing a digital assistant. In some examples, process 1100 is performed using a client-server system (e.g., system 100) and the blocks of process 1100 are divided up in any manner between the server (e.g., DA server 106) and a client device. In other examples, the blocks of process 1100 are divided up between the server and multiple client device (e.g., a mobile phone and a smart watch). Thus, while portion of process 1100 are described herein as being performed by particular device of a client-server system, it will be appreciated that process 1100 is not so limited. In other examples, process 1100 is performed using only a client device (e.g., user device 104) or only multiple client devices. In process 1100, some blocks are, optionally, combined, the order of some blocks is, optionally, changed, and some blocks are, optionally, omitted. In some examples, additional steps may be performed in combination with the process 1100.

With reference to FIG. 11A, at block 1102, mixed speech data (e.g., mixed speech data 801 in FIG. 8) are received. The mixed speech data represent utterances of a target speaker (e.g., utterances 801A) and utterances of one or more interfering audio sources (e.g., utterances 801B). The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. In some embodiments, the mixed speech data include acoustic representations of a plurality of audio frames corresponding to the utterances of the target speaker and the utterances of the one or more interfering audio sources. Each audio frame is associated with a predetermined period of time (e.g., 10 ms).

At block 1104, a target speaker representation (e.g., representation 824 in FIG. 8) is obtained. The target speaker representation represents speech characteristics of the target speaker. The target speaker representation is generated by a first learning network pre-trained for speaker verification (e.g., a dedicated LSTM-based speaker verification system). At block 1106, in some embodiments, to obtain the target speaker representation, enrollment utterances from the target speaker are received before receiving mixed speech data. At block 1108, a target speaker vector is determined based on the enrollment utterances from the target speaker.

At block 1110, in some embodiments, to obtain the target speaker representation, a trigger phrase uttered by the target speaker is received. The trigger phrase is part of the utterances represented by the mixed speech data (e.g., mixed speech data 801 in FIG. 8). At block 1112, a target speaker vector is determined based on the trigger phrase uttered by the target speaker.

At block 1114, using a second learning network (e.g., learning network 830 in FIG. 8), probability distributions of phonetic elements is determined directly from the mixed speech data. In some embodiments, inputs of the second learning network include the mixed speech data (e.g., mixed speech data 801 in FIG. 8) and the target speaker representation (representation 824 in FIG. 8). And an output of the second learning network includes the probability distributions of phonetic elements (e.g., senone posterior probability distributions 832 in FIG. 8).

At block 1116, to determine the probability distributions of phonetic elements directly from the mixed speech data, an intermedia representation (e.g., representation 842 in FIG. 8) of the mixed speech data is generated. At block 1118, to generate the intermediate representation, feature vectors (e.g., vectors 822) are extracted from a plurality of audio frames corresponding to the utterances represented by the mixed speech data. At block 1120, based on the extracted feature vectors, the intermediate representation of the mixed speech data are generated using the first portion of the second learning network (e.g., first portion 840 of learning network 830 in FIG. 8).

At block 1122, to generate the intermediate representation of the mixed speech data based on the extracted feature vectors, the extracted feature vectors are processed using the first portion of the second learning network (e.g., first portion 840 of learning network 830 in FIG. 8). The first portion of the second learning network includes a convolutional layer (e.g., layer 902 in FIGS. 9A and 9B)) and a pooling layer. At block 1124, the intermediate representation of the mixed speech data is obtained based on the processing results of the first portion of the second learning network.

With reference to FIG. 11B, at block 1126, using the second learning network, the probability distributions of phonetic elements are determined. In some examples, the second learning network is single learning network comprising a first portion (e.g., first portion 840 in FIG. 8) and a second portion (second portion 860 in FIG. 8). As described above, the probability distributions of phonetic elements can be, for example, senone posterior probability distributions 832 shown in FIG. 8.

In some examples, the second portion of the second learning network includes a first hidden layer of a first type (e.g., hidden layer 906A in FIG. 9A). At block 1128, a first hidden layer input (e.g., input to hidden layer 906A) is generated. The first hidden layer input includes a concatenation of the intermediate representation (e.g., an intermediate vector 904 in FIG. 9A) of the mixed speech data with the target speaker representation (e.g., representation 824 in FIG. 9A).

At block 1130, using a first hidden layer of the plurality of hidden layers of the first type, a first hidden layer output is determined based on the first hidden layer input. As shown in FIG. 9A, using hidden layer 906A, an output from layer 906A is determined based on the input to hidden layer 906A. In some examples, the second portion of the second learning network further includes a plurality of subsequent hidden layers of the first type (e.g., hidden layers 906B-N in FIG. 9A). At block 1132, for each subsequent hidden layer, a subsequent hidden layer input is generated (e.g., denoted by x in FIG. 9A). The input includes a concatenation of a preceding hidden layer output with the target speaker representation. At block 1134, for each subsequent hidden layer, a subsequent hidden layer output (e.g., denoted by y in FIG. 9A) is determined based on the concatenation of a preceding hidden layer output with the target speaker representation.

At block 1136, the probability distributions of phonetic elements (e.g., senone posterior probability distributions 832 in FIG. 9A) are determined based on a last hidden layer output associated with a last hidden layer of the first type (e.g., output of hidden layer 906N in FIG. 9A). In some examples, the phonetic elements include senones.

In some examples, the second portion of the second learning network includes a first hidden layer of a second type (e.g., hidden layer 916A in FIG. 9B). At block 1138, to determine the probability distributions of phonetic elements, the intermedia representation of the mixed speech data is projected to pairs of embedding vectors. The pairs of embedding vectors include acoustic embeddings and keys. For example, FIG. 9C illustrates projecting input 912 to embedding vectors 934A-M and keys 936A-M. At block 1140, for each acoustic embedding, a scalar coefficient (e.g., coefficient 939A-M in FIG. 9C) is determined based on the target speaker representation and a key corresponding to the acoustic embedding. At block 1142, a first hidden layer output is determined (e.g., output 962 in FIG. 9C) based on each acoustic embedding and the corresponding scalar coefficient for each acoustic embedding.

In some examples, the second portion of the second learning network (e.g., second portion 860B of learning network 830B) further includes a plurality of subsequent hidden layers of the second type (e.g., hidden layers 916B-N). With reference to FIG. 11C, at block 1144, a preceding hidden layer output (e.g., output of hidden layer 906A) is projected to pairs of additional embedding vectors. The pairs of additional embedding vectors include additional acoustic embeddings and additional keys. At block 1146, for each additional acoustic embedding, an additional scalar coefficient is determined based on the target speaker representation and an additional key corresponding to the additional acoustic embedding. At block 1148, a subsequent hidden layer output (e.g., output of hidden layer 916B) is determined based on each additional acoustic embedding and the corresponding additional scalar coefficient.

At block 1150, the probability distributions of phonetic elements are generated based on a last hidden layer output associated with a last hidden layer of the second type (e.g., the last hidden layer 916N shown in FIG. 9B). In some examples, the phonetic elements include senones.

At block 1152, text corresponding to the utterances of the target speaker (e.g., text 882 in FIG. 8) are generated based on the probability distributions of the phonetic elements. At block 1154, in some embodiments, to generate the text, beam-search decoding is performed based on the probability distributions of the phonetic elements.

At block 1156, a response to the target speaker is provided based on the text corresponding to the utterances of the target speaker. For example, at block 1158, a user intent is determined based on the text corresponding to the utterances of the target speaker. At block 1160, one or more tasks are performed based on the user intent.

FIGS. 12A-12D illustrate an exemplary process 1200 for training a speaker-aware acoustic model for speech recognition in a multi-speaker environment, according to various examples. Process 1200 is performed, for example, using one or more electronic devices implementing a digital assistant. In some examples, process 1200 is performed using a client-server system (e.g., system 100) and the blocks of process 1200 are divided up in any manner between the server (e.g., DA server 106) and a client device. In other examples, the blocks of process 1200 are divided up between the server and multiple client device (e.g., a mobile phone and a smart watch). Thus, while portion of process 1200 are described herein as being performed by particular device (e.g., a server) of a client-server system, it will be appreciated that process 1200 is not so limited. In other examples, process 1200 is performed using only a server system (e.g., server system 108) or only multiple service systems. In process 1200, some blocks are, optionally, combined, the order of some blocks is, optionally, changed, and some blocks are, optionally, omitted. In some examples, additional steps may be performed in combination with the process 1200.

With reference to FIG. 12A, at block 1202, prior to receiving a first set of training data (e.g., first set of training data 1006 in FIG. 10), utterances of the one or more interfering audio sources are obtained. As described below, a section set of training data is also received. As described above, and shown in FIG. 10, to obtain the first set of training data, at block 1204, utterances represented by the second set of training data and utterances the one or more interfering audio sources are acoustically mixed.

At block 1206, based on the mixing the second set of training data and the interfering audio sources, a first set of training data (e.g., first set of training data 1006 shown in FIG. 10) is received. The first set of training data represent utterances of a target speaker and utterances of one or more interfering audio sources. The utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap. In some examples, the first set of training data includes acoustic representations of a plurality of audio frames corresponding to the utterances of the target speaker and the one or more interfering audio sources. Each audio frame has a predetermined period of time (e.g., 10 ms).

At block 1208, a second set of training data is received. FIG. 10 illustrates a set of training data 1002. In some examples, the second set of training data represents only the utterances of the target speaker.

At block 1210, a target speaker representation (e.g., representation 1024 in FIG. 10) representing speech characteristics of the target speaker is obtained. The target speaker representation is generated by a first learning network pre-trained for speaker verification. In some examples, at block 1212, to obtain the target speaker representation, one or more utterances are selected from utterances represented by the second set of training data. At block 1214, a target speaker vector is determined based on selected one or more utterances. In some examples, the selected one or more utterances for generating the target speaker representation include trigger phrases followed by payloads (e.g., “Hey Assistant, what is the stock price today?”).

At block 1216, the speaker-aware acoustic model is trained for speech recognition based on the first set of training data and the second set of training data. In each iteration of the training, in some examples, the following steps can be performed. At block 1218, using a second learning network (e.g., learning network 830), probability distributions of phonetic elements are determined directly from the first set of training data. As shown in FIG. 10, the inputs of the second learning network include a portion of the first set of training data and the target speaker representation. An output of the second learning network includes the probability distributions of phonetic elements corresponding to the portion of the first set of training data.

At block 1220, to determine, using the second learning network, probability distributions of phonetic elements directly from the first set of training data, an intermediate representation (e.g., representation 842) of a portion of the first set of training data is generated. At block 1222, to generate the intermediate representation, feature vectors (e.g., vectors 822 in FIG. 10) are extracted from a plurality of audio frames corresponding the utterances represented by the portion of the first set of training data. With reference to FIG. 12B, at block 1224, based on the extracted feature vectors, the intermediate representation of the portion of the first set of training data is generated.

At block 1226, in some examples, to generate the intermediate representation of the portion of the first set of training data, the extracted feature vectors are processed using the first portion of the second learning network. The first portion of the second learning network includes a convolution layer and a pooling layer. At block 1228, the intermediate representation of the portion of the first set of training data is obtained based on the processing results of the first portion of the second learning network.

At block 1230, using the second learning network, the probability distributions of phonetic elements are determined. In some examples, the second portion of the second learning network includes a first hidden layer of a first type (e.g., hidden layer 906 shown in FIG. 9A). At block 1232, to determine the probability distributions of phonetic elements, a first hidden layer input is generated. The first hidden layer input includes a concatenation of the representation of the portion of the first set of training data with the target speaker representation. At block 1234, using a first hidden layer of the first type, a first hidden layer output is determined based on the first hidden layer input.

In some examples, the second portion of the second learning network further includes a plurality of subsequent hidden layers of the first type. For each subsequent hidden layer of the plurality of hidden layers of the first type, the process steps in blocks 1236-1238 are performed. At block 1236, a subsequent hidden layer input is generated. The subsequent hidden layer input includes a concatenation of a preceding hidden layer output with the target speaker representation. At block 1238, a subsequent hidden layer output is determined based on the concatenation of a preceding hidden layer output with the target speaker representation.

At block 1240, the probability distributions of phonetic elements are generated based on a last hidden layer output associated with a last hidden layer of the first type. In some examples, the phonetic elements include senones.

In some examples, the second portion of the second learning network (e.g., second portion 860 in FIG. 10) includes a first hidden layer of a second type (e.g., hidden layer 916 shown in FIGS. 9B and 9C). With reference to FIG. 12C, at block 122, the intermediate representation of the portion of the first set of training data is projected to pairs of embedding vectors. The pairs of embedding vectors include acoustic embeddings and keys. At block 1244, for each acoustic embedding, a scalar coefficient is determined based on the target speaker representation and a key corresponding to the acoustic embedding. At block 1246, a first hidden layer output is determined based on each acoustic embedding and the corresponding scalar coefficient for each acoustic embedding.

In some examples, the second portion of the second learning network further includes a plurality of subsequent hidden layers of the second type. At block 1248, a preceding hidden layer output is projected to pairs of additional embedding vectors. The pairs of additional vectors include acoustic embeddings and additional keys. At block 1250, for each additional acoustic embedding, an additional scalar coefficient is determined based on the target speaker representation and an additional key corresponding to the additional acoustic embedding. At block 1252, a subsequent hidden layer output is determined based on each additional acoustic embedding and the corresponding additional scalar coefficient. At block 1254, the probability distributions of phonetic elements are generated based on a last hidden layer output associated with a last hidden layer of the second type. The phonetic elements include senones.

With reference to FIG. 12D, at block 1256, text (e.g., text 1082 in FIG. 10) corresponding to the utterances of the target speaker in the portion of the first set of training data is generated based on the probability distributions of the phonetic elements corresponding to the portion of the first set of training data. In some examples, to generate the text, at block 1258, beam-search decoding is performed based on the probability distributions of the phonetic elements.

At block 1260, one or more parameters of the second learning network are adjusted based on the text corresponding to the utterances of the target speaker in the portion of the first set of training data and based on corresponding portion of the second set of training data. In some examples, to adjust the one or more parameters, at block 1262, text (e.g., text 1012) representation of the second set of training data is obtained. At block 1264, the differences between the generated text corresponding to the utterances of the target speaker in the portion of the first set of training data and the corresponding portion of the text representation of the second set of training data are determined. For example, the differences can be determined using a difference evaluator 1020 shown in FIG. 10). At block 1266, based on the determined differences, one or more parameters (e.g., weights and/or biases of a neural network) associated with the second portion of the second learning network are adjusted.

At block 1268, a trained speaker-aware acoustic model for speech recognition is provided to, for example, a user device. The speech recognition enables performing one or more tasks based on utterances of the target speaker.

In accordance with some implementations, a computer-readable storage medium (e.g., a non-transitory computer readable storage medium) is provided, the computer-readable storage medium storing one or more programs for execution by one or more processors of an electronic device, the one or more programs including instructions for performing any of the methods or processes described herein.

In accordance with some implementations, an electronic device (e.g., a portable electronic device) is provided that comprises means for performing any of the methods or processes described herein.

In accordance with some implementations, an electronic device (e.g., a portable electronic device) is provided that comprises a processing unit configured to perform any of the methods or processes described herein.

In accordance with some implementations, an electronic device (e.g., a portable electronic device) is provided that comprises one or more processors and memory storing one or more programs for execution by the one or more processors, the one or more programs including instructions for performing any of the methods or processes described herein.

The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the techniques and their practical applications. Others skilled in the art are thereby enabled to best utilize the techniques and various embodiments with various modifications as are suited to the particular use contemplated.

Although the disclosure and examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the claims.

As described above, one aspect of the present technology is the gathering and use of data available from various sources to improve the accuracy and efficiency of speech-to-text conversion of a target speaker in a multi-speaker environment. For example, sets of training data may be obtained for training a speaker-aware acoustic model. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include a particular user's utterances, demographic data, location-based data, telephone numbers, email addresses, twitter IDs, home addresses, data or records relating to a user's health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, or any other identifying or personal information.

The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to generate a target speaker vector such that the speech-to-text conversion based on the speaker-aware acoustic model is more accurate. Accordingly, use of such personal information data enables calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure.

The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country.

Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide mood-associated data for targeted content delivery services. In yet another example, users can select to limit the length of time mood-associated data is maintained or entirely prohibit the development of a baseline mood profile. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an app that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app.

Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user's privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data at a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods.

Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publicly available information. 

What is claimed is:
 1. A non-transitory computer-readable storage medium storing one or more programs, the one or more programs including instructions, which when executed by one or more processors of an electronic device, cause the electronic device to: receive mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources, wherein the utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap; obtain a target speaker representation representing speech characteristics of the target speaker, wherein the target speaker representation is generated by a first learning network pre-trained for speaker verification; determine, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data, wherein inputs of the second learning network include the mixed speech data and the target speaker representation, wherein an output of the learning network includes the probability distributions of phonetic elements, and wherein the first learning network and the second learning network are different learning networks; generate text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and provide a response based on the text corresponding to the utterances of the target speaker.
 2. The non-transitory computer-readable storage medium of claim 1, wherein the mixed speech data include acoustic representations of a plurality of audio frames corresponding to the utterances of the target speaker and the utterances of the one or more interfering audio sources, wherein each audio frame is associated with a predetermined period of time.
 3. The non-transitory computer-readable storage medium of claim 1, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving enrollment utterances from the target speaker before receiving mixed speech data; and determining a target speaker vector based on the enrollment utterances from the target speaker.
 4. The non-transitory computer-readable storage medium of claim 1, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving a trigger phrase uttered by the target speaker, wherein the trigger phrase is part of the utterances represented by the mixed speech data; and determining a target speaker vector based on the trigger phrase uttered by the target speaker.
 5. The non-transitory computer-readable storage medium of claim 1, wherein determining the probability distributions of phonetic elements directly from the mixed speech data comprises: generating an intermediate representation of the mixed speech data; and determining, using the second learning network, the probability distributions of phonetic elements, wherein the second learning network is single learning network comprising a first portion and a second portion.
 6. The non-transitory computer-readable storage medium of claim 5, wherein generating the intermediate representation of the mixed speech data comprises: extracting feature vectors from a plurality of audio frames corresponding to the utterances represented by the mixed speech data; and generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data using the first portion of the second learning network.
 7. The non-transitory computer-readable storage medium of claim 6, wherein generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data comprises: processing the extracted feature vectors using the first portion of the second learning network, wherein the first portion of the second learning network includes a convolutional layer and a pooling layer; and obtaining the intermediate representation of the mixed speech data based on the processing results of the first portion of the second learning network.
 8. The non-transitory computer-readable storage medium of claim 5, wherein the second portion of the second learning network includes a first hidden layer of a first type, and wherein determining the probability distributions of phonetic elements comprises: generating a first hidden layer input including a concatenation of the intermediate representation of the mixed speech data with the target speaker representation; and determining, using a first hidden layer of a plurality of hidden layers of the first type, a first hidden layer output based on the first hidden layer input.
 9. The non-transitory computer-readable storage medium of claim 8, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the first type, further comprising, for each subsequent hidden layer of the plurality of hidden layers of the first type: generating a subsequent hidden layer input including a concatenation of a preceding hidden layer output with the target speaker representation; and determining a subsequent hidden layer output based on the concatenation of a preceding hidden layer output with the target speaker representation.
 10. The non-transitory computer-readable storage medium of claim 9, wherein the one or more programs further include instructions, which when executed by the one or more processors of the electronic device, cause the electronic device to: generate the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the first type, wherein the phonetic elements include senones.
 11. The non-transitory computer-readable storage medium of claim 5, wherein the second portion of the second learning network includes a first hidden layer of a second type, and wherein determining the probability distributions of phonetic elements comprises, using the first hidden layer of the second type: projecting the intermedia representation of the mixed speech data to pairs of embedding vectors, wherein the pairs of embedding vectors include acoustic embeddings and keys; determining, for each acoustic embedding, a scalar coefficient based on the target speaker representation and a key corresponding to the acoustic embedding; and determining a first hidden layer output based on each acoustic embedding and the corresponding scalar coefficient for each acoustic embedding.
 12. The non-transitory computer-readable storage medium of claim 11, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the second type, and wherein the one or more programs further include instructions, which when executed by the one or more processors of the electronic device, cause the electronic device to: using each subsequent hidden layer of the plurality of hidden layers of the second type: project a preceding hidden layer output to pairs of additional embedding vectors, wherein the pairs of additional embedding vectors include additional acoustic embeddings and additional keys; determine, for each additional acoustic embedding, an additional scalar coefficient based on the target speaker representation and an additional key corresponding to the additional acoustic embedding; and determine a subsequent hidden layer output based on each additional acoustic embedding and the corresponding additional scalar coefficient.
 13. The non-transitory computer-readable storage medium of claim 12, wherein the one or more programs further include instructions, which when executed by the one or more processors of the electronic device, cause the electronic device to: generate the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the second type, wherein the phonetic elements include senones.
 14. The non-transitory computer-readable storage medium of claim 1, wherein generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements comprises: performing beam-search decoding based on the probability distributions of the phonetic elements.
 15. The non-transitory computer-readable storage medium of claim 1, wherein providing a response based on the text corresponding to the utterances of the target speaker comprises: determining a user intent based on the text corresponding to the utterances of the target speaker; and performing one or more tasks based on the user intent.
 16. A method for performing speech-to-text conversion in a multi-speaker environment by a virtual assistant, comprising: receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources, wherein the utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap; obtaining a target speaker representation representing speech characteristics of the target speaker, wherein the target speaker representation is generated by a first learning network pre-trained for speaker verification; determining, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data, wherein inputs of the second learning network include the mixed speech data and the target speaker representation, wherein an output of the learning network includes the probability distributions of phonetic elements, and wherein the first learning network and the second learning network are different learning networks; generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response based on the text corresponding to the utterances of the target speaker.
 17. The method of claim 16, wherein the mixed speech data includes acoustic representations of a plurality of audio frames corresponding to the utterances of the target speaker and the utterances of the one or more interfering audio sources, wherein each audio frame is associated with a predetermined period of time.
 18. The method of claim 16, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving enrollment utterances from the target speaker before receiving mixed speech data; and determining a target speaker vector based on the enrollment utterances from the target speaker.
 19. The method of claim 16, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving a trigger phrase uttered by the target speaker, wherein the trigger phrase is part of the utterances represented by the mixed speech data; and determining a target speaker vector based on the trigger phrase uttered by the target speaker.
 20. The method of claim 16, wherein determining the probability distributions of phonetic elements directly from the mixed speech data comprises: generating an intermediate representation of the mixed speech data; and determining, using the second learning network, the probability distributions of phonetic elements, wherein the second learning network is single learning network comprising a first portion and a second portion.
 21. The method of claim 20, wherein generating the intermediate representation of the mixed speech data comprises: extracting feature vectors from a plurality of audio frames corresponding to the utterances represented by the mixed speech data; and generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data using the first portion of the second learning network.
 22. The method of claim 21, wherein generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data comprises: processing the extracted feature vectors using the first portion of the second learning network, wherein the first portion of the second learning network includes a convolutional layer and a pooling layer; and obtaining the intermediate representation of the mixed speech data based on the processing results of the first portion of the second learning network.
 23. The method of claim 20, wherein the second portion of the second learning network includes a first hidden layer of a first type, and wherein determining the probability distributions of phonetic elements comprises: generating a first hidden layer input including a concatenation of the intermediate representation of the mixed speech data with the target speaker representation; and determining, using a first hidden layer of a plurality of hidden layers of the first type, a first hidden layer output based on the first hidden layer input.
 24. The method of claim 23, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the first type, further comprising, for each subsequent hidden layer of the plurality of hidden layers of the first type: generating a subsequent hidden layer input including a concatenation of a preceding hidden layer output with the target speaker representation; and determining a subsequent hidden layer output based on the concatenation of a preceding hidden layer output with the target speaker representation.
 25. The method of claim 24, further comprising: generating the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the first type, wherein the phonetic elements include senones.
 26. The method of claim 20, wherein the second portion of the second learning network includes a first hidden layer of a second type, and wherein determining the probability distributions of phonetic elements comprises, using the first hidden layer of the second type: projecting the intermedia representation of the mixed speech data to pairs of embedding vectors, wherein the pairs of embedding vectors include acoustic embeddings and keys; determining, for each acoustic embedding, a scalar coefficient based on the target speaker representation and a key corresponding to the acoustic embedding; and determining a first hidden layer output based on each acoustic embedding and the corresponding scalar coefficient for each acoustic embedding.
 27. The method of claim 26, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the second type, and further comprising: using each subsequent hidden layer of the plurality of hidden layers of the second type: projecting a preceding hidden layer output to pairs of additional embedding vectors, wherein the pairs of additional embedding vectors include additional acoustic embeddings and additional keys; determining, for each additional acoustic embedding, an additional scalar coefficient based on the target speaker representation and an additional key corresponding to the additional acoustic embedding; and determining a subsequent hidden layer output based on each additional acoustic embedding and the corresponding additional scalar coefficient.
 28. The method of claim 27, further comprising: generating the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the second type, wherein the phonetic elements include senones.
 29. The method of claim 16, wherein generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements comprises: performing beam-search decoding based on the probability distributions of the phonetic elements.
 30. The method of claim 16, wherein providing a response based on the text corresponding to the utterances of the target speaker comprises: determining a user intent based on the text corresponding to the utterances of the target speaker; and performing one or more tasks based on the user intent.
 31. An electronic device, comprising: one or more processors; memory; and one or more programs stored in memory, the one or more programs including instructions for: receiving mixed speech data representing utterances of a target speaker and utterances of one or more interfering audio sources, wherein the utterances of the target speaker and the utterances of the one or more interfering audio sources at least partially overlap; obtaining a target speaker representation representing speech characteristics of the target speaker, wherein the target speaker representation is generated by a first learning network pre-trained for speaker verification; determining, using a second learning network, probability distributions of phonetic elements directly from the mixed speech data, wherein inputs of the second learning network include the mixed speech data and the target speaker representation, wherein an output of the learning network includes the probability distributions of phonetic elements, and wherein the first learning network and the second learning network are different learning networks; generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements; and providing a response based on the text corresponding to the utterances of the target speaker.
 32. The electronic device of claim 31, wherein the mixed speech data include acoustic representations of a plurality of audio frames corresponding to the utterances of the target speaker and the utterances of the one or more interfering audio sources, wherein each audio frame is associated with a predetermined period of time.
 33. The electronic device of claim 31, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving enrollment utterances from the target speaker before receiving mixed speech data; and determining a target speaker vector based on the enrollment utterances from the target speaker.
 34. The electronic device of claim 31, wherein obtaining the target speaker representation representing speech characteristics of the target speaker comprises: receiving a trigger phrase uttered by the target speaker, wherein the trigger phrase is part of the utterances represented by the mixed speech data; and determining a target speaker vector based on the trigger phrase uttered by the target speaker.
 35. The electronic device of claim 31, wherein determining the probability distributions of phonetic elements directly from the mixed speech data comprises: generating an intermediate representation of the mixed speech data; and determining, using the second learning network, the probability distributions of phonetic elements, wherein the second learning network is single learning network comprising a first portion and a second portion.
 36. The electronic device of claim 35, wherein generating the intermediate representation of the mixed speech data comprises: extracting feature vectors from a plurality of audio frames corresponding to the utterances represented by the mixed speech data; and generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data using the first portion of the second learning network.
 37. The electronic device of claim 36, wherein generating, based on the extracted feature vectors, the intermediate representation of the mixed speech data comprises: processing the extracted feature vectors using the first portion of the second learning network, wherein the first portion of the second learning network includes a convolutional layer and a pooling layer; and obtaining the intermediate representation of the mixed speech data based on the processing results of the first portion of the second learning network.
 38. The electronic device of claim 35, wherein the second portion of the second learning network includes a first hidden layer of a first type, and wherein determining the probability distributions of phonetic elements comprises: generating a first hidden layer input including a concatenation of the intermediate representation of the mixed speech data with the target speaker representation; and determining, using a first hidden layer of a plurality of hidden layers of the first type, a first hidden layer output based on the first hidden layer input.
 39. The electronic device of claim 38, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the first type, further comprising, for each subsequent hidden layer of the plurality of hidden layers of the first type: generating a subsequent hidden layer input including a concatenation of a preceding hidden layer output with the target speaker representation; and determining a subsequent hidden layer output based on the concatenation of a preceding hidden layer output with the target speaker representation.
 40. The electronic device of claim 39, further comprising: generating the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the first type, wherein the phonetic elements include senones.
 41. The electronic device of claim 35, wherein the second portion of the second learning network includes a first hidden layer of a second type, and wherein determining the probability distributions of phonetic elements comprises, using the first hidden layer of the second type: projecting the intermedia representation of the mixed speech data to pairs of embedding vectors, wherein the pairs of embedding vectors include acoustic embeddings and keys; determining, for each acoustic embedding, a scalar coefficient based on the target speaker representation and a key corresponding to the acoustic embedding; and determining a first hidden layer output based on each acoustic embedding and the corresponding scalar coefficient for each acoustic embedding.
 42. The electronic device of claim 41, wherein the second portion of the second learning network further includes a plurality of subsequent hidden layers of the second type, and further comprising: using each subsequent hidden layer of the plurality of hidden layers of the second type: projecting a preceding hidden layer output to pairs of additional embedding vectors, wherein the pairs of additional embedding vectors include additional acoustic embeddings and additional keys; determining, for each additional acoustic embedding, an additional scalar coefficient based on the target speaker representation and an additional key corresponding to the additional acoustic embedding; and determining a subsequent hidden layer output based on each additional acoustic embedding and the corresponding additional scalar coefficient.
 43. The electronic device of claim 42, further comprising: generating the probability distributions of phonetic elements based on a last hidden layer output associated with a last hidden layer of the second type, wherein the phonetic elements include senones.
 44. The electronic device of claim 31, wherein generating text corresponding to the utterances of the target speaker based on the probability distributions of the phonetic elements comprises: performing beam-search decoding based on the probability distributions of the phonetic elements.
 45. The electronic device of claim 31, wherein providing a response based on the text corresponding to the utterances of the target speaker comprises: determining a user intent based on the text corresponding to the utterances of the target speaker; and performing one or more tasks based on the user intent. 